Enstatite
Mg2Si2O6IMA symbol: Enapproved
Enstatite is a silicate mineral with the formula Mg2Si2O6, crystallizing in the orthorhombic system. It has a Mohs hardness of 5.5, typically white, brown, gray or green in color, with a pearly or vitreous luster, a specific gravity of 3.1-3.3. Its streak is gray or red.
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/c 1 |
| Cell (Å, °) | a = 9.713, b = 8.91, c = 5.238; α = 90, β = 109.41, γ = 90 |
| Cell volume | 427.547 ų, Z = 8 |
| Axial ratios | 1.0901:1:0.5879calculated from COD 9001220 |
| Source structure | COD 9001220 (American Mineralogist, 1989) — 1 of 90 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.02 | 2.889 | 3.194 | 2.47 | 2.927 | 2.144 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 50.7 | 49 | 46.2 | 38.7 | 35.5 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9001220; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.38 g/cm³calculated from COD 9001220 |
|---|---|
| Hardness (Mohs) | 5.5single sourceWikidata (CC0) 5.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3.1-3.3 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, gray, green, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | greysingle sourceWikidata (CC0) gray, redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | pearly, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 200.78 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mg 24.21%, Si 27.98%, O 47.81% |
Classification
| Nickel-Strunz (10th) | 9.DA.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.DA.05Wikidata (CC0) |
| Dana (8th) | 65.1.2.1Wikidata (CC0) |