GreenSpar anorthosite lunar highlands simulant GreenSpar

Calcium-rich plagioclase feldspar rock (anorthosite) from the White Mountain deposit in Greenland, about 94 wt% plagioclase by CIPW norm, with minor pyroxene and quartz. The end member anorthite is CaAl₂Si₂O₈. · Triclinic, P 1 (low), anorthite end member

Also known as GreenSpar, GreenSpar 250, GreenSpar 90

GreenSpar is a surface anorthosite from Greenland, sold in two size fractions (GreenSpar 250 and GreenSpar 90) as a lunar highlands simulant component.

8 sources · Updated 2026-11-02 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Recipe, share of the weight

94%Plagioclase feldspar (calcium-rich, AN 83)
SiO2 1 to 5%Quartz (silicon dioxide, crystalline)
5%Pyroxene

Best for

Early geotechnical, abrasion and dust tests that need a plagioclase-rich highlands material, where the full lunar particle size distribution is not required (NASA ARES recommendation).

Weakest at

Lunar particle size and glass content: ARES says it does not replicate the particle size distribution of lunar regolith and has no agglutinate or glass component.

Risk at a glance

People High. Hazardous: contains crystalline silica
If it fails No data. No failure risks recorded
Corrosion No data. No corrosion data recorded

Quick facts: GreenSpar

Key properties of GreenSpar
Property	Value	Basis
Density	2.6 g/cm³	1 sourced value
Melting point	1,300 to 1,350 °C	1 sourced value

What is the density of GreenSpar anorthosite lunar highlands simulant?

GreenSpar anorthosite lunar highlands simulant has a density of 2.6 g/cm³. The source and test conditions are listed in the properties table on this page.

What is the melting point of GreenSpar anorthosite lunar highlands simulant?

GreenSpar anorthosite lunar highlands simulant has a melting point of 1,300 to 1,350 °C. The source and test conditions are listed in the properties table on this page.

What are the other names and codes for GreenSpar anorthosite lunar highlands simulant?

GreenSpar anorthosite lunar highlands simulant is also written as GreenSpar, GreenSpar 250, GreenSpar 90. Each code is printed in the source listed beside it in the designations table.

What is GreenSpar anorthosite lunar highlands simulant used for?

Uses recorded in the sources include Loose and compacted soil beds for geotechnical tests; Samples for dust mitigation and abrasion tests; Early tests of high-temperature processes (sintering and oxygen or metal production).

Why it exists

GreenSpar is the name Hudson Resources uses for a surface anorthosite mined at its White Mountain Anorthosite Project in Greenland. NASA uses it as a basic lunar highlands simulant: one rock type with no glass component. Its CIPW norm gives 94 wt% plagioclase and an AN number of 83, which resembles the lunar highlands. It was chosen as a cheap, readily available highlands component for early mechanical and dust work, not as a full copy of lunar soil. ARES describes it as among the most readily available sources of large quantities of anorthosite.

Where it's used

Geotechnical testing

NASA ARES recommends GreenSpar for geotechnical tests with loose or compacted simulant.

Dust and abrasion testing

ARES also recommends it for dust mitigation and abrasion tests. Gruener et al. (2020) say its quartz content may help simulate the abrasiveness of lunar regolith.

High-temperature process tests

The NASA users guide says early sintering and oxygen or metal production work can use GreenSpar as a basic simulant, before moving to a more lunar-like enhanced simulant.

Recipe

GreenSpar is a rock, not one compound. It is an anorthosite made mostly of calcium-rich plagioclase feldspar (CIPW norm 94 wt%, X-ray diffraction about 82 wt%), with minor pyroxene (about 5 wt%) and quartz (about 7 wt% by XRD). Anorthosite is an intrusive igneous rock made mostly of plagioclase feldspar (Wikipedia). The product is sold in two size fractions, GreenSpar 250 and GreenSpar 90.

What GreenSpar is made of
Ingredient	Share of the weight	What it does
Plagioclase feldspar (calcium-rich, AN 83)	94%	Main mineral; the calcium-rich feldspar that gives the simulant its highlands-like chemistry.
Quartz (silicon dioxide, crystalline) SiO2	1 to 5%	Crystalline silica: adds abrasiveness and is the source of the crystalline silica hazard.
Pyroxene	5%	Minor mafic mineral in the rock.

Weight shares are as printed in the sources.

What it can do

Geotechnical tests

Loose or compacted beds of GreenSpar are the use ARES recommends first, with a specific gravity of 2.6 g/cm3 on its page.

Abrasion

ARES gives a Mohs hardness of 6 to 6.5 and says the quartz content makes it a strong abradant. Quartz is about 7 wt% by XRD in Gruener et al. (2020).

Particle size

For GreenSpar 250, the NASA users guide gives Q25, Q50 and Q75 values of 37.5, 78 and 141.2 µm (Clark 2021, JSC-ARES). ARES says the material does not replicate the particle size distribution of lunar regolith.

Crystalline silica

The 2022 analysis in the NASA users guide gives 6.37 wt% total crystalline silica and 0.16 wt% respirable crystalline silica. The SDS gives quartz as 1 to 5 wt%, so the lot in use should be measured.

How it compares

NASA's users guide ranks GreenSpar as a basic simulant, which means one rock type, no glass component and no attempt to match the lunar particle size distribution. Enhanced highlands simulants such as NUW-LHT-5M add synthetic glass to match Apollo 16 soil chemistry, so they are closer to lunar soil; the users guide notes that cost rises as more lunar attributes are added. The table below sets out how GreenSpar's particle size, density and silica figures compare with the properties recorded here.

The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details.

Benchmarks
Measurement	GreenSpar
Thermal behavior and safety
Loss on heating up to 1000 °C	0.8 wt%²¹
Melting point, product as named on the SDS (Calcium Feldspar)	1300 to 1350 °C³⁴
Physical and electrical
Hardness (Mohs scale)	6 to 6.5 Mohs scale²
Other measurements
Specific gravity	2.6 g/cm³¹
Particle size range, as printed	5 to 250 µm³
Plagioclase, modal abundance (ARES)	> 90 vol%⁴
Silicon dioxide (GreenSpar Hudson Resources column)	50.69 wt%⁵
Aluminium oxide (GreenSpar Hudson Resources column)	30.47 wt%⁶
Iron(III) oxide (GreenSpar Hudson Resources column)	0.44 wt%⁷
Magnesium oxide (GreenSpar Hudson Resources column)	0.31 wt%⁸
Calcium oxide (GreenSpar Hudson Resources column)	14.64 wt%⁹
Sodium oxide (GreenSpar Hudson Resources column)	2.44 wt%¹⁰
Potassium oxide (GreenSpar Hudson Resources column)	0.19 wt%¹¹
Plagioclase content, CIPW norm	94 wt%¹²
AN number (plagioclase anorthite content index)	83 -¹³
Silicon dioxide (Gruener et al. Table 1 average)	50.18 wt%¹⁴
Aluminium oxide (Gruener et al. Table 1 average)	30.88 wt%¹⁵
Calcium oxide (Gruener et al. Table 1 average)	14.58 wt%¹⁶
Sodium oxide (Gruener et al. Table 1 average)	2.63 wt%¹⁷
Plagioclase content, X-ray diffraction	82 wt%¹⁸
Pyroxene content, as stated	5 wt%¹⁹
Quartz content, as stated	7 wt%²⁰
Particle size range, laser analysis	3 to 250 µm²²
Mean particle size, graphical mean	76 µm²³
Silicon dioxide (Wilson, USGS 2020, as tabulated by NASA)	51 wt%²⁴
Aluminium oxide (Wilson, USGS 2020, as tabulated by NASA)	30.6 wt%²⁵
Calcium oxide (Wilson, USGS 2020, as tabulated by NASA)	14.7 wt%²⁶
Particle size, 25th quartile (Q25), GreenSpar 250	37.5 µm²⁷
Particle size, median (Q50), GreenSpar 250	78 µm²⁸
Particle size, 75th quartile (Q75), GreenSpar 250	141.2 µm²⁹
Particle aspect ratio (bulk, image analysis)	0.62 -³⁰
Root form factor (bulk, image analysis)	0.9 -³¹
Total crystalline silica, 2022 analysis	6.37 wt%³²
Total respirable crystalline silica, 2022 analysis	0.16 wt%³³
Quartz (silicon dioxide), average weight share on the SDS	1 to 5 wt%³⁵
Feldspar, average weight share on the SDS	95 to 99 wt%³⁶
pH of a water suspensionRange printed in SDS Section 9, pH row	9 to 10 -

Why choose it, and why not

Good for

Geotechnical tests with loose or compacted material, which ARES recommends first.
Abrasion and dust tests where a quartz-bearing, plagioclase-rich material is wanted.

Watch out for

Particle size: ARES says it does not replicate the particle size distribution of lunar regolith and is available only in fine sizes.
Silica: the 2022 analysis gives 6.37 wt% total crystalline silica, but the SDS gives quartz as 1 to 5 wt%, so do not assume the lower figure.
Oxide chemistry differs by source: SiO2 is 50.69 wt% in the Hudson column, 50.18 wt% in the Gruener et al. table and 51 wt% in the NASA users guide.
No glass or agglutinate: ARES lists this as a con, and the users guide says a higher-fidelity simulant would need glass.

A basic highlands simulant for early geotechnical, abrasion and dust tests. It is not a match for lunar particle size or glass content.

Technical details

For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.

Other names and standards

The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.

Other names and standards
System	Codes
Trade name	GreenSpar, GreenSpar 250 (product size, below 250 µm), GreenSpar 90 (product size, below 90 µm)

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#	Measurement	Method	Conditions	Caveat
1	Specific gravity	Value printed on the ARES GreenSpar page, Geomechanical Properties table, Specific Gravity column	basis value printed in the ARES Geomechanical Properties table for GreenSpar; no test method is given on the page	—
2	Hardness (Mohs scale)	Range printed on the ARES GreenSpar page, Geomechanical Properties table, Hardness column	state range as printed on the ARES GreenSpar page	—
3	Particle size range, as printed	Range printed on the ARES GreenSpar page, General Properties table, Particle Size Range column	basis printed as < 5 - 250 µm; the lower end is a less-than limit, so 5 is the printed limit and not a measured minimum	Gruener et al. (2020) give a laser-based range of 3 to 250 µm for the same material (see the next group of rows).
4	Plagioclase, modal abundance (ARES)	Value printed on the ARES GreenSpar page, Modal Mineralogy table, GreenSpar Abundance column, Plagioclase row	basis printed as > 90 vol% in the ARES Modal Mineralogy table; no method is given	The Gruener et al. (2020) X-ray diffraction value for plagioclase is about 82 wt%, a different basis (weight, not volume); both are kept.
5	Silicon dioxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
6	Aluminium oxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
7	Iron(III) oxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
8	Magnesium oxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
9	Calcium oxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
10	Sodium oxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
11	Potassium oxide (GreenSpar Hudson Resources column)	Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column	basis major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page	—
12	Plagioclase content, CIPW norm	Value stated in the Introduction of the Gruener et al. (2020) abstract, Greenland anorthosite paragraph	basis CIPW norm calculated from the Hudson Resources XRF chemistry, as reported by Gruener et al. (2020)material GreenSpar, White Mountain anorthosite, Greenland	—
13	AN number (plagioclase anorthite content index)	Value stated in the Introduction of the Gruener et al. (2020) abstract, Greenland anorthosite paragraph	basis AN number as printed in the Gruener et al. (2020) abstract; the paper gives no unit	—
14	Silicon dioxide (Gruener et al. Table 1 average)	Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, SiO2 row	basis average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page	—
15	Aluminium oxide (Gruener et al. Table 1 average)	Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, Al2O3 row	basis average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page	—
16	Calcium oxide (Gruener et al. Table 1 average)	Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, CaO row	basis average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page	—
17	Sodium oxide (Gruener et al. Table 1 average)	Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, Na2O row	basis average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page	—
18	Plagioclase content, X-ray diffraction	Value stated in the Greenland anorthosite paragraph of the Gruener et al. (2020) abstract	basis approximately 82 wt% by X-ray diffraction, whole pattern fitting and Rietveld refinement (Knudsen et al. data as cited by Gruener et al.)	The paper gives the value as approximately 82 wt%; it is a different method and basis from the CIPW norm of 94 wt%, and both are kept.
19	Pyroxene content, as stated	Value stated in the CIPW Norm paragraph of the Gruener et al. (2020) abstract	basis approximately 5 wt% pyroxene, as stated in the Gruener et al. (2020) abstract	—
20	Quartz content, as stated	Value stated in the CIPW Norm paragraph of the Gruener et al. (2020) abstract	basis approximately 7 wt% quartz, as stated in the Gruener et al. (2020) abstract	Quartz is about 7 wt% here, against 1 to 5 wt% on the supplier SDS and 6.37 wt% total crystalline silica in the NASA users guide.
21	Loss on heating up to 1000 °C	Value stated in the Introduction of the Gruener et al. (2020) abstract, thermal and evolved gas analysis paragraph	basis approximately 0.8 wt% loss through heating up to 1000 °C, as stated in the Gruener et al. (2020) abstract	CO2 is the most significant gas released, probably from the calcite present in the material, according to the abstract.
22	Particle size range, laser analysis	Range stated in the Greenland anorthosite paragraph of the Gruener et al. (2020) abstract	basis laser particle size distribution of the GreenSpar 250 material, as stated by Gruener et al. (2020)	—
23	Mean particle size, graphical mean	Value stated in the Greenland anorthosite paragraph of the Gruener et al. (2020) abstract	basis graphical mean from laser particle size analysis of GreenSpar 250, as stated by Gruener et al. (2020)	—
24	Silicon dioxide (Wilson, USGS 2020, as tabulated by NASA)	Value printed in the Table 7 GreenSpar row, SiO2 column, of the NASA users guide	basis bulk chemistry of GreenSpar as tabulated in the NASA users guide, reference Wilson USGS 2020material GreenSpar, Highlands region	Differs from the 50.69 wt% (Hudson column) and 50.18 wt% (Gruener et al.) values; the three are kept side by side.
25	Aluminium oxide (Wilson, USGS 2020, as tabulated by NASA)	Value printed in the Table 7 GreenSpar row, Al2O3 column, of the NASA users guide	basis bulk chemistry of GreenSpar as tabulated in the NASA users guide, reference Wilson USGS 2020material GreenSpar, Highlands region	—
26	Calcium oxide (Wilson, USGS 2020, as tabulated by NASA)	Value printed in the Table 7 GreenSpar row, CaO column, of the NASA users guide	basis bulk chemistry of GreenSpar as tabulated in the NASA users guide, reference Wilson USGS 2020material GreenSpar, Highlands region	—
27	Particle size, 25th quartile (Q25), GreenSpar 250	Value printed in the Table 10 GreenSpar (250µm) row, Q25 column, of the NASA users guide	basis average Q25 of percent passing grains for GreenSpar (250 µm), reference Clark 2021 (JSC-ARES)region Highlands	—
28	Particle size, median (Q50), GreenSpar 250	Value printed in the Table 10 GreenSpar (250µm) row, Q50 column, of the NASA users guide	basis average Q50 of percent passing grains for GreenSpar (250 µm), reference Clark 2021 (JSC-ARES)region Highlands	The Gruener et al. graphical mean is 76 µm on a different basis; the two are kept.
29	Particle size, 75th quartile (Q75), GreenSpar 250	Value printed in the Table 10 GreenSpar (250µm) row, Q75 column, of the NASA users guide	basis average Q75 of percent passing grains for GreenSpar (250 µm), reference Clark 2021 (JSC-ARES)region Highlands	—
30	Particle aspect ratio (bulk, image analysis)	Value printed in the Table 13 GreenSpar row, AR column, of the NASA users guide	basis bulk AR value, SDL 2022 (JSC-ARES) particle images, as printed in the NASA users guide	—
31	Root form factor (bulk, image analysis)	Value printed in the Table 13 GreenSpar row, root FF column, of the NASA users guide	basis bulk root form factor value printed as 0.90, SDL 2022 (JSC-ARES) particle images	—
32	Total crystalline silica, 2022 analysis	Value printed in Table 25, GreenSpar (Greenland Anorthosite) row, Total Percent Crystalline Silica column, of the NASA users guide	basis total percent crystalline silica for GreenSpar (Greenland Anorthosite), analysis symbol printed as § (2022); the symbol key is not in the text read	The same table gives 3.33 percent passing under 10 µm, which the printed table does not give a unit for, so it is not recorded here.
33	Total respirable crystalline silica, 2022 analysis	Value printed in Table 25, GreenSpar (Greenland Anorthosite) row, Total Respirable Crystalline Silica column, of the NASA users guide	basis total respirable crystalline silica for GreenSpar (Greenland Anorthosite), analysis symbol printed as § (2022)	—
34	Melting point, product as named on the SDS (Calcium Feldspar)	Range printed in SDS Section 9 (Physical and Chemical Properties), Melting Point row	basis range printed as 1300 - 1350°C on the supplier SDS, whose product name is Calcium Feldspar	—
35	Quartz (silicon dioxide), average weight share on the SDS	Range printed in SDS Section 3 (Composition), Silicon Dioxide, Quartz row	basis average weight share printed as 1 – 5% in the SDS Section 3 table, column Average WT %	The SDS lists this as Silicon Dioxide, Quartz with CAS 14808-60-7; the NASA users guide gives 6.37 wt% total crystalline silica for a different analysis.
36	Feldspar, average weight share on the SDS	Range printed in SDS Section 3 (Composition), Feldspar row	basis average weight share printed as 95 - 99% in the SDS Section 3 table, column Average WT %	The CIPW norm gives 94 wt% plagioclase and XRD gives about 82 wt% plagioclase; the three figures are on different bases and are all kept.

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
Environment	Concern	What happens
Contact with other materials in storage and use	not rated	No incompatibility or corrosion test data for GreenSpar in the sources read.¹

Corrosion details
#	Environment	Details	Test conditions
1	Contact with other materials in storage and use	The supplier SDS prints 'MATERIALS WITH WHICH SUBSTANCE IS INCOMPATIBLE: None known' and 'STABILITY: Product is stable', but it gives no corrosion test data. The same SDS gives a pH of 9 to 10 in water suspension, so a wet mix is alkaline.	basis SDS statements only; no test on GreenSpar with any metal, coating or electrolyte was found

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

The supplier SDS carries signal word Danger, mainly because the powder contains crystalline silica.

Dust: The SDS says dust is irritating to the eyes, skin and respiratory system, and advises local exhaust ventilation and goggles where dusting is possible.
Lungs and cancer: The SDS says the material contains crystalline silica, a known carcinogen, and that prolonged inhalation can cause silicosis.
Exposure limits: The SDS prints OSHA TWA 15mg/m³ total dust and 0.1 mg/m³ respirable fraction for inert minerals.

Clean-up and storage

Dust control matters most when the powder is moved, poured or cleaned up.

Clean-up: Use a HEPA vacuum or wet the dust first; the SDS says to avoid dry sweeping and compressed air.
Wet mixes: A water suspension has a pH of 9 to 10 according to the SDS, so it is alkaline.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
Failure	Trigger and consequence
Crystalline silica content differs between sources	Using the simulant for dust or health studies without a current analysis of the lot in useThe NASA users guide gives 6.37 wt% total crystalline silica (2022 analysis), the SDS gives quartz as 1 – 5% by weight, and Gruener et al. (2020) state about 7 wt% quartz by XRD. Test results and exposure assessments should use a measured value for the lot in use.
Particle size does not match lunar regolith	Testing that needs the lunar particle size distribution, such as excavation with pebbles and cobblesARES lists as a con that GreenSpar does not replicate the particle size distribution of lunar regolith and is only available in small particle sizes. The users guide says excavation work needs the full particle size distribution of the bulk regolith.
No glass or agglutinate component	Sintering, dust or surface tests that depend on glass or agglutinate particlesARES lists 'No agglutinate or glass component' as a con. Gruener et al. (2020) state that a higher-fidelity simulant would likely need glass, other rocks or minerals, and agglutinates added to GreenSpar.

Side effects on surrounding parts

Side effects on surrounding parts
Affects	Effect
Vacuum and high-temperature rigs, and sample weight measurements	Heating releases gas; the abstract gives about 0.8 wt% loss through heating up to 1000 °C, with CO2 the most significant gas, probably from calcite.
Operators and the test rig surroundings	The SDS says 'Dust may cause eye, nasal or bronchial irritation' in the Section 11 symptoms of exposure.

Handling and storage

Use local exhaust ventilation to control airborne dust, and wear safety glasses or chemical goggles where dusting is possible.
Clean up dry powder with a HEPA vacuum or by wetting it with water; avoid dry sweeping and compressed air.
Wash skin after handling, and do not eat, drink or smoke while handling the product.

Mitigations

Use respiratory protection only where it is authorised under the OSHA respiratory protection standard, when airborne concentrations cannot be kept below the listed guidelines.

Supply and geography

How common the raw materials are and where they come from.

Feldspar (plagioclase, the main mineral group in GreenSpar)

The USGS feldspar chapter gives world mine production of about 31,000 thousand t in 2025 (estimated, rounded), with the leading producing countries accounting for 74% of the world total.

Top producers (2025): India 19.4%, Turkey 17.1%, Iran 12.6%, China 11.9%, Italy 7.1%, Thailand 6.1%
Critical mineral lists: EU: listed
Recycling: USGS: feldspar and nepheline syenite are not recycled by producers, although glass container producers use cullet, which reduces feldspar consumption.
Substitutes: USGS: feldspar can be replaced in some end uses by clays, electric furnace slag, feldspar-silica mixtures, pyrophyllite, spodumene, or talc.

Anorthosite (GreenSpar feedstock, Greenland)

Top producers: Greenland
Recycling: Not stated in the sources read.

Documents

Datasheets, safety data sheets, papers and standards you can open.

Documents
Document	Type	Year
GreenSpar Safety Data Sheet (Hudson Resources; product named Calcium Feldspar), rev. 2, September 24, 2019	sds	2019
NASA JSC ARES: Lunar regolith simulants, GreenSpar	datasheet	2021
Lunar Regolith Simulant User's Guide, Rev. A (NASA/TM-20240011783)	report	2024
Gruener et al. (2020), Greenland White Mountain anorthosite: a new lunar polar regolith simulant component (LPSC 2020 abstract 2867)	paper	2020
USGS Mineral Commodity Summaries 2026: Feldspar and nepheline syenite	report	2026
Handbook of Mineralogy: anorthite (Mineral Data Publishing)	database	2001

Full record

The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.

Show the full YAML

spore: profile
id: greenspar-anorthosite-simulant
spore_version: 0.2
family: regolith
name: GreenSpar anorthosite lunar highlands simulant
abbreviation: GreenSpar
role: Basic physical simulant of lunar highlands soil for geotechnical, abrasion and dust tests
category: regolith
type: lunar-simulants
summary: GreenSpar is a surface anorthosite from Greenland, sold in two size fractions (GreenSpar 250 and GreenSpar 90) as a lunar highlands simulant component. The Gruener et al. (2020) abstract gives a CIPW norm of 94 wt% plagioclase and an AN number of 83, which resemble the lunar highlands. It has no glass or agglutinate, and its size distribution does not copy lunar regolith.
best_for: Early geotechnical, abrasion and dust tests that need a plagioclase-rich highlands material, where the full lunar particle size distribution is not required (NASA ARES recommendation).
weakest_at: 'Lunar particle size and glass content: ARES says it does not replicate the particle size distribution of lunar regolith and has no agglutinate or glass component.'
identity:
  formula: Calcium-rich plagioclase feldspar rock (anorthosite) from the White Mountain deposit in Greenland, about 94 wt% plagioclase by CIPW norm, with minor pyroxene and quartz. The end member anorthite is CaAl2Si2O8.
  crystal_system: Triclinic (anorthite end member)
  space_group: P 1 (low), anorthite end member
  source: handbook-anorthite
  where: 'Mineral Data Publishing handbook entry for anorthite: Chemistry line (CaAl2 Si2 O8) and Cell Data (space group)'
  designations:
    - system: Trade name
      code: GreenSpar
      source: ares-greenspar
      where: Overview paragraph
    - system: Trade name
      code: GreenSpar 250
      note: product size, below 250 µm
      source: ares-greenspar
      where: Overview paragraph
    - system: Trade name
      code: GreenSpar 90
      note: product size, below 90 µm
      source: ares-greenspar
      where: Overview paragraph
tags:
  environments: []
  stresses: []
  applications:
    - rovers-and-surface-systems
    - mechanisms
    - in-space-manufacturing
properties:
  - benchmark: specific_gravity
    label: Specific gravity
    value: 2.6
    unit: g/cm3
    scope: material
    conditions:
      basis: value printed in the ARES Geomechanical Properties table for GreenSpar; no test method is given on the page
    method: Value printed on the ARES GreenSpar page, Geomechanical Properties table, Specific Gravity column
    status: ground
    source: ares-greenspar
    where: Geomechanical Properties table, Specific Gravity (g/cm 3) column
  - benchmark: hardness
    label: Hardness (Mohs scale)
    value: 6
    value_high: 6.5
    bound: range
    unit: Mohs scale
    scope: material
    conditions:
      state: range as printed on the ARES GreenSpar page
    method: Range printed on the ARES GreenSpar page, Geomechanical Properties table, Hardness column
    status: ground
    source: ares-greenspar
    where: Geomechanical Properties table, Hardness (Mohs scale) column
  - benchmark: particle_size_range
    label: Particle size range, as printed
    value: 5
    value_high: 250
    bound: range
    unit: µm
    scope: material
    conditions:
      basis: printed as < 5 - 250 µm; the lower end is a less-than limit, so 5 is the printed limit and not a measured minimum
    method: Range printed on the ARES GreenSpar page, General Properties table, Particle Size Range column
    status: ground
    note: Gruener et al. (2020) give a laser-based range of 3 to 250 µm for the same material (see the next group of rows).
    source: ares-greenspar
    where: General Properties table, Particle Size Range (µm) column
  - benchmark: plagioclase_modal
    label: Plagioclase, modal abundance (ARES)
    value: 90
    bound: lower
    unit: vol%
    scope: material
    conditions:
      basis: printed as > 90 vol% in the ARES Modal Mineralogy table; no method is given
    method: Value printed on the ARES GreenSpar page, Modal Mineralogy table, GreenSpar Abundance column, Plagioclase row
    status: ground
    note: The Gruener et al. (2020) X-ray diffraction value for plagioclase is about 82 wt%, a different basis (weight, not volume); both are kept.
    source: ares-greenspar
    where: Modal Mineralogy table, Plagioclase row
  - benchmark: sio2
    label: Silicon dioxide (GreenSpar Hudson Resources column)
    value: 50.69
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, SiO2 row, GreenSpar (Hudson Resources) column
  - benchmark: al2o3
    label: Aluminium oxide (GreenSpar Hudson Resources column)
    value: 30.47
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, Al2O3 row, GreenSpar (Hudson Resources) column
  - benchmark: fe2o3
    label: Iron(III) oxide (GreenSpar Hudson Resources column)
    value: 0.44
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, Fe2O3 row, GreenSpar (Hudson Resources) column
  - benchmark: mgo
    label: Magnesium oxide (GreenSpar Hudson Resources column)
    value: 0.31
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, MgO row, GreenSpar (Hudson Resources) column
  - benchmark: cao
    label: Calcium oxide (GreenSpar Hudson Resources column)
    value: 14.64
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, CaO row, GreenSpar (Hudson Resources) column
  - benchmark: na2o
    label: Sodium oxide (GreenSpar Hudson Resources column)
    value: 2.44
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, Na2O row, GreenSpar (Hudson Resources) column
  - benchmark: k2o
    label: Potassium oxide (GreenSpar Hudson Resources column)
    value: 0.19
    unit: wt%
    scope: material
    conditions:
      basis: major-element analysis from the supplier, column printed as GreenSpar (Hudson Resources) on the ARES page
    method: Value printed on the ARES GreenSpar page, Major Element Chemistry table, Hudson Resources column
    status: ground
    source: ares-greenspar
    where: Major Element Chemistry table, K2O row, GreenSpar (Hudson Resources) column
  - benchmark: plagioclase_cipw_norm
    label: Plagioclase content, CIPW norm
    value: 94
    unit: wt%
    scope: material
    conditions:
      basis: CIPW norm calculated from the Hudson Resources XRF chemistry, as reported by Gruener et al. (2020)
      material: GreenSpar, White Mountain anorthosite, Greenland
    method: Value stated in the Introduction of the Gruener et al. (2020) abstract, Greenland anorthosite paragraph
    status: ground
    source: gruener-2020
    where: Introduction, Greenland anorthosite paragraph; CIPW Norm paragraph
  - benchmark: an_number
    label: AN number (plagioclase anorthite content index)
    value: 83
    unit: '-'
    scope: material
    conditions:
      basis: AN number as printed in the Gruener et al. (2020) abstract; the paper gives no unit
    method: Value stated in the Introduction of the Gruener et al. (2020) abstract, Greenland anorthosite paragraph
    status: ground
    source: gruener-2020
    where: Introduction, Greenland anorthosite paragraph
  - benchmark: sio2
    label: Silicon dioxide (Gruener et al. Table 1 average)
    value: 50.18
    unit: wt%
    scope: material
    conditions:
      basis: average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page
    method: Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, SiO2 row
    status: ground
    source: gruener-2020
    where: Table 1, Major Oxides, SiO2 row
  - benchmark: al2o3
    label: Aluminium oxide (Gruener et al. Table 1 average)
    value: 30.88
    unit: wt%
    scope: material
    conditions:
      basis: average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page
    method: Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, Al2O3 row
    status: ground
    source: gruener-2020
    where: Table 1, Major Oxides, Al2O3 row
  - benchmark: cao
    label: Calcium oxide (Gruener et al. Table 1 average)
    value: 14.58
    unit: wt%
    scope: material
    conditions:
      basis: average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page
    method: Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, CaO row
    status: ground
    source: gruener-2020
    where: Table 1, Major Oxides, CaO row
  - benchmark: na2o
    label: Sodium oxide (Gruener et al. Table 1 average)
    value: 2.63
    unit: wt%
    scope: material
    conditions:
      basis: average weight percent, XRF data provided by Hudson Resources; column GreenSpar [1] on the ARES page
    method: Value printed in Table 1 of the Gruener et al. (2020) abstract, Major Oxides, Na2O row
    status: ground
    source: gruener-2020
    where: Table 1, Major Oxides, Na2O row
  - benchmark: plagioclase_xrd
    label: Plagioclase content, X-ray diffraction
    value: 82
    unit: wt%
    scope: material
    conditions:
      basis: approximately 82 wt% by X-ray diffraction, whole pattern fitting and Rietveld refinement (Knudsen et al. data as cited by Gruener et al.)
    method: Value stated in the Greenland anorthosite paragraph of the Gruener et al. (2020) abstract
    status: ground
    note: The paper gives the value as approximately 82 wt%; it is a different method and basis from the CIPW norm of 94 wt%, and both are kept.
    source: gruener-2020
    where: Introduction, CIPW Norm paragraph (XRD sentence)
  - benchmark: pyroxene_xrd
    label: Pyroxene content, as stated
    value: 5
    unit: wt%
    scope: material
    conditions:
      basis: approximately 5 wt% pyroxene, as stated in the Gruener et al. (2020) abstract
    method: Value stated in the CIPW Norm paragraph of the Gruener et al. (2020) abstract
    status: ground
    source: gruener-2020
    where: Introduction, CIPW Norm paragraph
  - benchmark: quartz_xrd
    label: Quartz content, as stated
    value: 7
    unit: wt%
    scope: material
    conditions:
      basis: approximately 7 wt% quartz, as stated in the Gruener et al. (2020) abstract
    method: Value stated in the CIPW Norm paragraph of the Gruener et al. (2020) abstract
    status: ground
    note: Quartz is about 7 wt% here, against 1 to 5 wt% on the supplier SDS and 6.37 wt% total crystalline silica in the NASA users guide.
    source: gruener-2020
    where: Introduction, CIPW Norm paragraph
  - benchmark: mass_loss_on_heating
    label: Loss on heating up to 1000 °C
    value: 0.8
    unit: wt%
    scope: material
    conditions:
      basis: approximately 0.8 wt% loss through heating up to 1000 °C, as stated in the Gruener et al. (2020) abstract
    method: Value stated in the Introduction of the Gruener et al. (2020) abstract, thermal and evolved gas analysis paragraph
    status: ground
    note: CO2 is the most significant gas released, probably from the calcite present in the material, according to the abstract.
    source: gruener-2020
    where: Introduction, thermal and evolved gas analysis paragraph
  - benchmark: particle_size_range
    label: Particle size range, laser analysis
    value: 3
    value_high: 250
    bound: range
    unit: µm
    scope: material
    conditions:
      basis: laser particle size distribution of the GreenSpar 250 material, as stated by Gruener et al. (2020)
    method: Range stated in the Greenland anorthosite paragraph of the Gruener et al. (2020) abstract
    status: ground
    source: gruener-2020
    where: Greenland anorthosite paragraph (particle size range sentence)
  - benchmark: mean_particle_size
    label: Mean particle size, graphical mean
    value: 76
    unit: µm
    scope: material
    conditions:
      basis: graphical mean from laser particle size analysis of GreenSpar 250, as stated by Gruener et al. (2020)
    method: Value stated in the Greenland anorthosite paragraph of the Gruener et al. (2020) abstract
    status: ground
    source: gruener-2020
    where: Greenland anorthosite paragraph (particle size sentence)
  - benchmark: sio2
    label: Silicon dioxide (Wilson, USGS 2020, as tabulated by NASA)
    value: 51
    unit: wt%
    scope: material
    conditions:
      basis: bulk chemistry of GreenSpar as tabulated in the NASA users guide, reference Wilson USGS 2020
      material: GreenSpar, Highlands region
    method: Value printed in the Table 7 GreenSpar row, SiO2 column, of the NASA users guide
    status: ground
    note: Differs from the 50.69 wt% (Hudson column) and 50.18 wt% (Gruener et al.) values; the three are kept side by side.
    source: nasa-guide-2024
    where: Table 7 (Lunar regolith simulant bulk chemistry), GreenSpar row, SiO2 column
  - benchmark: al2o3
    label: Aluminium oxide (Wilson, USGS 2020, as tabulated by NASA)
    value: 30.6
    unit: wt%
    scope: material
    conditions:
      basis: bulk chemistry of GreenSpar as tabulated in the NASA users guide, reference Wilson USGS 2020
      material: GreenSpar, Highlands region
    method: Value printed in the Table 7 GreenSpar row, Al2O3 column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 7 (Lunar regolith simulant bulk chemistry), GreenSpar row, Al2O3 column
  - benchmark: cao
    label: Calcium oxide (Wilson, USGS 2020, as tabulated by NASA)
    value: 14.7
    unit: wt%
    scope: material
    conditions:
      basis: bulk chemistry of GreenSpar as tabulated in the NASA users guide, reference Wilson USGS 2020
      material: GreenSpar, Highlands region
    method: Value printed in the Table 7 GreenSpar row, CaO column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 7 (Lunar regolith simulant bulk chemistry), GreenSpar row, CaO column
  - benchmark: particle_size_q25
    label: Particle size, 25th quartile (Q25), GreenSpar 250
    value: 37.5
    unit: µm
    scope: material
    conditions:
      basis: average Q25 of percent passing grains for GreenSpar (250 µm), reference Clark 2021 (JSC-ARES)
      region: Highlands
    method: Value printed in the Table 10 GreenSpar (250µm) row, Q25 column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 10 (Lunar regolith simulant PSD), GreenSpar (250µm) row, Q25 column
  - benchmark: median_particle_size_d50
    label: Particle size, median (Q50), GreenSpar 250
    value: 78
    unit: µm
    scope: material
    conditions:
      basis: average Q50 of percent passing grains for GreenSpar (250 µm), reference Clark 2021 (JSC-ARES)
      region: Highlands
    method: Value printed in the Table 10 GreenSpar (250µm) row, Q50 column, of the NASA users guide
    status: ground
    note: The Gruener et al. graphical mean is 76 µm on a different basis; the two are kept.
    source: nasa-guide-2024
    where: Table 10 (Lunar regolith simulant PSD), GreenSpar (250µm) row, Q50 column
  - benchmark: particle_size_q75
    label: Particle size, 75th quartile (Q75), GreenSpar 250
    value: 141.2
    unit: µm
    scope: material
    conditions:
      basis: average Q75 of percent passing grains for GreenSpar (250 µm), reference Clark 2021 (JSC-ARES)
      region: Highlands
    method: Value printed in the Table 10 GreenSpar (250µm) row, Q75 column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 10 (Lunar regolith simulant PSD), GreenSpar (250µm) row, Q75 column
  - benchmark: aspect_ratio
    label: Particle aspect ratio (bulk, image analysis)
    value: 0.62
    unit: '-'
    scope: material
    conditions:
      basis: bulk AR value, SDL 2022 (JSC-ARES) particle images, as printed in the NASA users guide
    method: Value printed in the Table 13 GreenSpar row, AR column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 13 (Lunar regolith simulant particle geometry), GreenSpar row, AR column
  - benchmark: sqrt_form_factor
    label: Root form factor (bulk, image analysis)
    value: 0.9
    unit: '-'
    scope: material
    conditions:
      basis: bulk root form factor value printed as 0.90, SDL 2022 (JSC-ARES) particle images
    method: Value printed in the Table 13 GreenSpar row, root FF column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 13 (Lunar regolith simulant particle geometry), GreenSpar row, root FF column
  - benchmark: crystalline_silica_total
    label: Total crystalline silica, 2022 analysis
    value: 6.37
    unit: wt%
    scope: material
    conditions:
      basis: total percent crystalline silica for GreenSpar (Greenland Anorthosite), analysis symbol printed as § (2022); the symbol key is not in the text read
    method: Value printed in Table 25, GreenSpar (Greenland Anorthosite) row, Total Percent Crystalline Silica column, of the NASA users guide
    status: ground
    note: The same table gives 3.33 percent passing under 10 µm, which the printed table does not give a unit for, so it is not recorded here.
    source: nasa-guide-2024
    where: Table 25 (Summary of total percent crystalline and respirable silica), GreenSpar (Greenland Anorthosite) row
  - benchmark: respirable_crystalline_silica
    label: Total respirable crystalline silica, 2022 analysis
    value: 0.16
    unit: wt%
    scope: material
    conditions:
      basis: total respirable crystalline silica for GreenSpar (Greenland Anorthosite), analysis symbol printed as § (2022)
    method: Value printed in Table 25, GreenSpar (Greenland Anorthosite) row, Total Respirable Crystalline Silica column, of the NASA users guide
    status: ground
    source: nasa-guide-2024
    where: Table 25 (Summary of total percent crystalline and respirable silica), GreenSpar (Greenland Anorthosite) row
  - benchmark: melting_point
    label: Melting point, product as named on the SDS (Calcium Feldspar)
    value: 1300
    value_high: 1350
    bound: range
    unit: °C
    scope: material
    conditions:
      basis: range printed as 1300 - 1350°C on the supplier SDS, whose product name is Calcium Feldspar
    method: Range printed in SDS Section 9 (Physical and Chemical Properties), Melting Point row
    status: ground
    source: sds-greenspar
    where: Section 9, MELTING POINT row
  - benchmark: quartz_content
    label: Quartz (silicon dioxide), average weight share on the SDS
    value: 1
    value_high: 5
    bound: range
    unit: wt%
    scope: material
    conditions:
      basis: average weight share printed as 1 – 5% in the SDS Section 3 table, column Average WT %
    method: Range printed in SDS Section 3 (Composition), Silicon Dioxide, Quartz row
    status: ground
    note: The SDS lists this as Silicon Dioxide, Quartz with CAS 14808-60-7; the NASA users guide gives 6.37 wt% total crystalline silica for a different analysis.
    source: sds-greenspar
    where: Section 3, Silicon Dioxide, Quartz row, Average WT % column
  - benchmark: feldspar_content
    label: Feldspar, average weight share on the SDS
    value: 95
    value_high: 99
    bound: range
    unit: wt%
    scope: material
    conditions:
      basis: average weight share printed as 95 - 99% in the SDS Section 3 table, column Average WT %
    method: Range printed in SDS Section 3 (Composition), Feldspar row
    status: ground
    note: The CIPW norm gives 94 wt% plagioclase and XRD gives about 82 wt% plagioclase; the three figures are on different bases and are all kept.
    source: sds-greenspar
    where: Section 3, Feldspar row, Average WT % column
  - benchmark: ph
    label: pH of a water suspension
    value: 9
    value_high: 10
    bound: range
    unit: '-'
    scope: material
    conditions:
      basis: printed as 9 – 10 in water suspension on the SDS; pH is a dimensionless number
    method: Range printed in SDS Section 9, pH row
    status: ground
    source: sds-greenspar
    where: Section 9, pH row
corrosion:
  - environment: Contact with other materials in storage and use
    headline: No incompatibility or corrosion test data for GreenSpar in the sources read.
    effect: 'The supplier SDS prints ''MATERIALS WITH WHICH SUBSTANCE IS INCOMPATIBLE: None known'' and ''STABILITY: Product is stable'', but it gives no corrosion test data. The same SDS gives a pH of 9 to 10 in water suspension, so a wet mix is alkaline.'
    rating: unknown
    conditions:
      basis: SDS statements only; no test on GreenSpar with any metal, coating or electrolyte was found
    source: sds-greenspar
    where: Section 9 (pH row) and Section 10 (Stability and Reactivity)
risks:
  hazards:
    - text: The SDS carries signal word Danger and lists GHS classes STOT RE Category 1, Carcinogenicity Category 1B, Skin Irritant Category 2, Eye Irritant Category 2 and STOT SE Category 3, with the hazard statements 'Causes damage to organs through prolonged or repeated exposure', 'May cause cancer', 'Causes skin irritation', 'Causes serious eye irritation' and 'May cause respiratory irritation'.
      ghs:
        - H319
        - H335
        - H340
        - H373
      source: sds-greenspar
      where: Section 2 (GHS Hazard Classification and Hazard Statements); the H-codes come from the Section 3 ingredients table, which prints H319, H335, H340 and H373 for feldspar and quartz
    - text: The SDS states 'This product contains Crystalline Silica which is a known carcinogen' and that prolonged or repeated inhalation of respirable crystalline silica from this product 'can cause silicosis, a seriously disabling and fatal lung disease'.
      ghs: []
      source: sds-greenspar
      where: Section 2 (Chronic) and Section 11 (Toxicological Information, Silicosis)
    - text: The SDS prints exposure limits for inert minerals of ACGIH TWA 10mg/m³ Total Dust, OSHA TWA 15mg/m³ Total Dust and 0.1 mg/m³ Respirable Fraction, with the silicon dioxide, quartz row giving its own limits.
      ghs: []
      source: sds-greenspar
      where: Section 8 (Exposure Limits/Guidelines) table
    - text: The SDS says 'Exposure to the solid product can be irritating to eyes and skin. Dust generated can be irritating to the respiratory system.'
      ghs: []
      source: sds-greenspar
      where: Section 2 (Emergency Overview)
  failure_risks:
    - mode: Crystalline silica content differs between sources
      trigger: Using the simulant for dust or health studies without a current analysis of the lot in use
      consequence: The NASA users guide gives 6.37 wt% total crystalline silica (2022 analysis), the SDS gives quartz as 1 – 5% by weight, and Gruener et al. (2020) state about 7 wt% quartz by XRD. Test results and exposure assessments should use a measured value for the lot in use.
      source: nasa-guide-2024
      where: Table 25, GreenSpar row; SDS Section 3; Gruener et al. CIPW Norm paragraph
    - mode: Particle size does not match lunar regolith
      trigger: Testing that needs the lunar particle size distribution, such as excavation with pebbles and cobbles
      consequence: ARES lists as a con that GreenSpar does not replicate the particle size distribution of lunar regolith and is only available in small particle sizes. The users guide says excavation work needs the full particle size distribution of the bulk regolith.
      source: ares-greenspar
      where: Cons list on the ARES GreenSpar page
    - mode: No glass or agglutinate component
      trigger: Sintering, dust or surface tests that depend on glass or agglutinate particles
      consequence: ARES lists 'No agglutinate or glass component' as a con. Gruener et al. (2020) state that a higher-fidelity simulant would likely need glass, other rocks or minerals, and agglutinates added to GreenSpar.
      source: ares-greenspar
      where: Cons list on the ARES GreenSpar page; Gruener et al. Discussion
  side_effects:
    - text: Heating releases gas; the abstract gives about 0.8 wt% loss through heating up to 1000 °C, with CO2 the most significant gas, probably from calcite.
      affects: Vacuum and high-temperature rigs, and sample weight measurements
      source: gruener-2020
      where: Thermal and evolved gas analysis paragraph
    - text: The SDS says 'Dust may cause eye, nasal or bronchial irritation' in the Section 11 symptoms of exposure.
      affects: Operators and the test rig surroundings
      source: sds-greenspar
      where: Section 11 (Toxicological Information), Irritancy and Symptoms of Exposure
  handling:
    - text: Use local exhaust ventilation to control airborne dust, and wear safety glasses or chemical goggles where dusting is possible.
      source: sds-greenspar
      where: Section 8 (Ventilation and Engineering Controls; Eye Protection)
    - text: Clean up dry powder with a HEPA vacuum or by wetting it with water; avoid dry sweeping and compressed air.
      source: sds-greenspar
      where: Section 6 (Spills) and Section 7 (Storage and Handling Practices)
    - text: Wash skin after handling, and do not eat, drink or smoke while handling the product.
      source: sds-greenspar
      where: Section 7 (Work Practices and Hygiene Practices)
  mitigations:
    - text: Use respiratory protection only where it is authorised under the OSHA respiratory protection standard, when airborne concentrations cannot be kept below the listed guidelines.
      source: sds-greenspar
      where: Section 8 (Respiratory Protection)
uses:
  - application: rovers-and-surface-systems
    device: Loose and compacted soil beds for geotechnical tests
    example: ARES recommends GreenSpar for geotechnical testing that involves loose or compacted simulant.
    source: ares-greenspar
    where: Recommendation section
  - application: mechanisms
    device: Samples for dust mitigation and abrasion tests
    example: ARES also recommends GreenSpar for dust and dust mitigation testing and for abrasion testing. Gruener et al. (2020) say the quartz in it may help simulate the abrasiveness of lunar regolith.
    source: ares-greenspar
    where: Recommendation section; Gruener et al. Discussion
  - application: in-space-manufacturing
    device: Early tests of high-temperature processes (sintering and oxygen or metal production)
    example: The NASA users guide says early high-temperature process work, including laser or microwave sintering, can use a basic simulant such as GreenSpar before moving to an enhanced simulant.
    source: nasa-guide-2024
    where: Section 3.7.1 (High Temperature Processes)
supply:
  - subject: Feldspar (plagioclase, the main mineral group in GreenSpar)
    abundance: The USGS feldspar chapter gives world mine production of about 31,000 thousand t in 2025 (estimated, rounded), with the leading producing countries accounting for 74% of the world total.
    producers:
      - country: India
        share_percent: 19.4
        year: 2025
      - country: Turkey
        share_percent: 17.1
        year: 2025
      - country: Iran
        share_percent: 12.6
        year: 2025
      - country: China
        share_percent: 11.9
        year: 2025
      - country: Italy
        share_percent: 7.1
        year: 2025
      - country: Thailand
        share_percent: 6.1
        year: 2025
    critical_lists:
      - list: EU critical raw materials list (Regulation (EU) 2024/1252), where the EC page prints Feldspar among the listed materials
        listed: true
    recycling: 'USGS: feldspar and nepheline syenite are not recycled by producers, although glass container producers use cullet, which reduces feldspar consumption.'
    substitutes:
      - 'USGS: feldspar can be replaced in some end uses by clays, electric furnace slag, feldspar-silica mixtures, pyrophyllite, spodumene, or talc.'
    source: usgs-mcs2026-feldspar
    where: World Mine Production and Reserves table, 2025 column (shares calculated by Space Mushroom against the printed world total of 31,000 thousand t); Recycling; Substitutes; EU list on the EC critical raw materials page
  - subject: Anorthosite (GreenSpar feedstock, Greenland)
    producers:
      - country: Greenland
    critical_lists: []
    recycling: Not stated in the sources read.
    substitutes: []
    source: gruener-2020
    where: 'Greenland anorthosite paragraph: Hudson Resources mines surface-exposed anorthosite at the White Mountain Anorthosite Project, about 85 km southwest of Kangerlussuaq; the ARES page says the material is primarily mined for E-glass, paint, coating fillers, alumina and white cement'
media: []
documents:
  - title: GreenSpar Safety Data Sheet (Hudson Resources; product named Calcium Feldspar), rev. 2, September 24, 2019
    type: sds
    url: https://ares.jsc.nasa.gov/projects/simulants/_resources/GreenSpar_CalciumFeldspar_SDS_9_24_2019.pdf
    year: 2019
  - title: 'NASA JSC ARES: Lunar regolith simulants, GreenSpar'
    type: datasheet
    url: https://ares.jsc.nasa.gov/projects/simulants/greenspar.html
    year: 2021
  - title: Lunar Regolith Simulant User's Guide, Rev. A (NASA/TM-20240011783)
    type: report
    url: https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf
    year: 2024
  - title: 'Gruener et al. (2020), Greenland White Mountain anorthosite: a new lunar polar regolith simulant component (LPSC 2020 abstract 2867)'
    type: paper
    url: https://www.hou.usra.edu/meetings/lpsc2020/pdf/2867.pdf
    year: 2020
  - title: 'USGS Mineral Commodity Summaries 2026: Feldspar and nepheline syenite'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-feldspar.pdf
    year: 2026
  - title: 'Handbook of Mineralogy: anorthite (Mineral Data Publishing)'
    type: database
    url: https://www.handbookofmineralogy.org/pdfs/anorthite.pdf
    year: 2001
gaps:
  - Density (rho min and rho max) for GreenSpar is blank in Table 16 of the NASA users guide, so no value is recorded.
  - Cohesion and friction angle for GreenSpar are marked n/a in Table 19 of the NASA users guide, and no other shear strength value was found.
  - Magnetic susceptibility for GreenSpar (Table 22 of the NASA users guide) is printed as a log of a value in 10-9 m3/kg, which is an exponent form, so it is not recorded.
  - The percent passing under 10 µm for GreenSpar in Table 25 of the NASA users guide has no printed unit, so it is not recorded.
  - The SDS gives calcium as between 14% and 16% without saying whether it is elemental or as oxide; the ARES calcium oxide values (14.58 and 14.64 wt%) are not comparable with it, so the calcium figure is not recorded.
  - The ARES page says Simulant Development Lab analytical results are pending, so no lab-measured result for this lot was found.
  - No corrosion, ageing, vacuum, radiation, thermal-cycling or flight test of GreenSpar was found in the sources read.
  - The USGS 2025 List of Critical Minerals page returned an access block (HTTP 403) during this run, so feldspar was checked only against the EU critical raw materials list.
  - No production tonnage or country share for the Greenland anorthosite itself was found; the USGS shares are for feldspar as a whole.
  - The oxide sets from the ARES Hudson column, the ARES and Gruener et al. GreenSpar [1] column, and the NASA users guide Table 7 (Wilson 2020) differ from one another, and no single preferred set was identified; all are kept with their sources.
  - No photograph of GreenSpar with a verified licence was fetched in this run, so the page has no media entry.
sources:
  ares-greenspar:
    title: 'NASA JSC ARES, Lunar Regolith Simulants: GreenSpar'
    url: https://ares.jsc.nasa.gov/projects/simulants/greenspar.html
    year: 2021
    kind: datasheet
    license: NASA public web page
  gruener-2020:
    title: 'Greenland ''White Mountain'' anorthosite: a new lunar polar regolith simulant component (51st LPSC, abstract 2867)'
    id: LPSC 2020, abstract 2867; J. E. Gruener et al.
    url: https://www.hou.usra.edu/meetings/lpsc2020/pdf/2867.pdf
    year: 2020
    kind: paper
    license: Conference abstract, cited not reproduced
  nasa-guide-2024:
    title: Lunar Regolith Simulant User's Guide, Revision A
    id: NASA/TM-20240011783 (NTRS 20240011783)
    url: https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf
    year: 2024
    kind: report
    license: public domain (NASA)
  sds-greenspar:
    title: Safety Data Sheet, Calcium Feldspar (Hudson Resources Inc.), Rev 2
    id: SDS dated January 11, 2016, last revised September 24, 2019
    url: https://ares.jsc.nasa.gov/projects/simulants/_resources/GreenSpar_CalciumFeldspar_SDS_9_24_2019.pdf
    year: 2019
    kind: datasheet
    license: supplier document, linked not reproduced
  usgs-mcs2026-feldspar:
    title: 'Mineral Commodity Summaries 2026: Feldspar and Nepheline Syenite'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-feldspar.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  handbook-anorthite:
    title: 'Handbook of Mineralogy: Anorthite'
    id: Mineral Data Publishing, version 1.2
    url: https://www.handbookofmineralogy.org/pdfs/anorthite.pdf
    year: 2001
    kind: handbook
    license: all rights reserved by Mineral Data Publishing, cited
  ec-crm:
    title: Critical raw materials (European Commission, list under Regulation (EU) 2024/1252)
    id: Regulation (EU) 2024/1252
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2024
    kind: web
    license: European Commission web page
  wikipedia-anorthosite:
    title: Anorthosite (Wikipedia)
    url: https://en.wikipedia.org/wiki/Anorthosite
    kind: web
    license: CC BY-SA 4.0 (Wikipedia)
license: CC-BY-4.0
updated: '2026-11-02'
review:
  status: draft
  method: assistant
  checked_values: 37
  unreachable: 0
  caveats: 6
  note: Read in one run on 2026-11-02 from the ARES page, the NASA users guide PDF, the Gruener et al. LPSC 2020 abstract, the supplier SDS, the USGS feldspar summary, the Handbook of Mineralogy entry and the EC critical raw materials page. Values that differ between sources are kept side by side.
story:
  why: 'GreenSpar is the name Hudson Resources uses for a surface anorthosite mined at its White Mountain Anorthosite Project in Greenland. NASA uses it as a basic lunar highlands simulant: one rock type with no glass component. Its CIPW norm gives 94 wt% plagioclase and an AN number of 83, which resembles the lunar highlands. It was chosen as a cheap, readily available highlands component for early mechanical and dust work, not as a full copy of lunar soil. ARES describes it as among the most readily available sources of large quantities of anorthosite.'
  uses:
    - where: Geotechnical testing
      line: NASA ARES recommends GreenSpar for geotechnical tests with loose or compacted simulant.
    - where: Dust and abrasion testing
      line: ARES also recommends it for dust mitigation and abrasion tests. Gruener et al. (2020) say its quartz content may help simulate the abrasiveness of lunar regolith.
    - where: High-temperature process tests
      line: The NASA users guide says early sintering and oxygen or metal production work can use GreenSpar as a basic simulant, before moving to a more lunar-like enhanced simulant.
  can_do:
    - label: Geotechnical tests
      line: Loose or compacted beds of GreenSpar are the use ARES recommends first, with a specific gravity of 2.6 g/cm3 on its page.
    - label: Abrasion
      line: ARES gives a Mohs hardness of 6 to 6.5 and says the quartz content makes it a strong abradant. Quartz is about 7 wt% by XRD in Gruener et al. (2020).
    - label: Particle size
      line: For GreenSpar 250, the NASA users guide gives Q25, Q50 and Q75 values of 37.5, 78 and 141.2 µm (Clark 2021, JSC-ARES). ARES says the material does not replicate the particle size distribution of lunar regolith.
    - label: Crystalline silica
      line: The 2022 analysis in the NASA users guide gives 6.37 wt% total crystalline silica and 0.16 wt% respirable crystalline silica. The SDS gives quartz as 1 to 5 wt%, so the lot in use should be measured.
  compare: NASA's users guide ranks GreenSpar as a basic simulant, which means one rock type, no glass component and no attempt to match the lunar particle size distribution. Enhanced highlands simulants such as NUW-LHT-5M add synthetic glass to match Apollo 16 soil chemistry, so they are closer to lunar soil; the users guide notes that cost rises as more lunar attributes are added. The table below sets out how GreenSpar's particle size, density and silica figures compare with the properties recorded here.
  compare_rows:
    - label: Density (specific gravity)
      benchmark: specific_gravity
    - label: Median particle size
      Q50: null
      benchmark: median_particle_size_d50
    - label: Total crystalline silica
      2022 analysis: null
      benchmark: crystalline_silica_total
  handling:
    - Use local exhaust ventilation and wear safety glasses or goggles where dust is possible (SDS Section 8).
    - Clean up dust with a HEPA vacuum or wet it first; do not dry sweep or use compressed air (SDS Sections 6 and 7).
    - 'Do not treat the powder as silica-free: the SDS says it contains crystalline silica, a known carcinogen.'
    - Wash after handling and keep food and drink out of the work area.
  good_for:
    - Geotechnical tests with loose or compacted material, which ARES recommends first.
    - Abrasion and dust tests where a quartz-bearing, plagioclase-rich material is wanted.
  watch_out:
    - 'Particle size: ARES says it does not replicate the particle size distribution of lunar regolith and is available only in fine sizes.'
    - 'Silica: the 2022 analysis gives 6.37 wt% total crystalline silica, but the SDS gives quartz as 1 to 5 wt%, so do not assume the lower figure.'
    - 'Oxide chemistry differs by source: SiO2 is 50.69 wt% in the Hudson column, 50.18 wt% in the Gruener et al. table and 51 wt% in the NASA users guide.'
    - 'No glass or agglutinate: ARES lists this as a con, and the users guide says a higher-fidelity simulant would need glass.'
  verdict: A basic highlands simulant for early geotechnical, abrasion and dust tests. It is not a match for lunar particle size or glass content.
  risk_groups:
    - title: For people
      lead: The supplier SDS carries signal word Danger, mainly because the powder contains crystalline silica.
      level: 3
      verdict: 'Hazardous: contains crystalline silica'
      points:
        - label: Dust
          line: The SDS says dust is irritating to the eyes, skin and respiratory system, and advises local exhaust ventilation and goggles where dusting is possible.
        - label: Lungs and cancer
          line: The SDS says the material contains crystalline silica, a known carcinogen, and that prolonged inhalation can cause silicosis.
        - label: Exposure limits
          line: The SDS prints OSHA TWA 15mg/m³ total dust and 0.1 mg/m³ respirable fraction for inert minerals.
    - title: Clean-up and storage
      lead: Dust control matters most when the powder is moved, poured or cleaned up.
      level: 1
      verdict: Use HEPA or wet clean-up
      points:
        - label: Clean-up
          line: Use a HEPA vacuum or wet the dust first; the SDS says to avoid dry sweeping and compressed air.
        - label: Wet mixes
          line: A water suspension has a pH of 9 to 10 according to the SDS, so it is alkaline.
  recipe:
    line: GreenSpar is a rock, not one compound. It is an anorthosite made mostly of calcium-rich plagioclase feldspar (CIPW norm 94 wt%, X-ray diffraction about 82 wt%), with minor pyroxene (about 5 wt%) and quartz (about 7 wt% by XRD). Anorthosite is an intrusive igneous rock made mostly of plagioclase feldspar (Wikipedia). The product is sold in two size fractions, GreenSpar 250 and GreenSpar 90.
    parts:
      - name: Plagioclase feldspar (calcium-rich, AN 83)
        role: Main mineral; the calcium-rich feldspar that gives the simulant its highlands-like chemistry.
        share_percent: 94
        source: gruener-2020
        where: Introduction, CIPW Norm paragraph (CIPW norm); XRD gives about 82 wt%
      - name: Quartz (silicon dioxide, crystalline)
        symbol: SiO2
        role: 'Crystalline silica: adds abrasiveness and is the source of the crystalline silica hazard.'
        share_percent: 1
        share_high: 5
        source: sds-greenspar
        where: Section 3, Silicon Dioxide, Quartz row, Average WT % column
      - name: Pyroxene
        role: Minor mafic mineral in the rock.
        share_percent: 5
        source: gruener-2020
        where: Introduction, CIPW Norm paragraph (XRD sentence)

References

Every number above carries a reference number. Click one to see the source and where in it the value comes from.

References
Source	Type	Year	Used for
NASA JSC ARES, Lunar Regolith Simulants: GreenSpar	datasheet	2021	15 values
Greenland 'White Mountain' anorthosite: a new lunar polar regolith simulant component (51st LPSC, abstract 2867)	paper	2020	14 values
Lunar Regolith Simulant User's Guide, Revision A	report	2024	12 values
Safety Data Sheet, Calcium Feldspar (Hudson Resources Inc.), Rev 2	datasheet	2019	14 values
Mineral Commodity Summaries 2026: Feldspar and Nepheline Syenite	report	2026	1 value
Handbook of Mineralogy: Anorthite	handbook	2001	1 value
Critical raw materials (European Commission, list under Regulation (EU) 2024/1252)	web	2024	0 values
Anorthosite (Wikipedia)	web		0 values

References
Identity
Formula	Calcium-rich plagioclase feldspar rock (anorthosite) from the White Mountain deposit in Greenland, about 94 wt% plagioclase by CIPW norm, with minor pyroxene and quartz. The end member anorthite is CaAl2Si2O8.
Crystal system	Triclinic (anorthite end member)
Space group	P 1 (low), anorthite end member
Role	Basic physical simulant of lunar highlands soil for geotechnical, abrasion and dust tests
Benchmarks	37

References
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Updated 5 November 2026