Sepiolite
Mg4Si6O15(OH)2·6H2OIMA symbol: Sepgrandfathered
Sepiolite is a silicate mineral with the formula Mg4Si6O15(OH)2·6H2O, crystallizing in the orthorhombic system. It has a Mohs hardness of 2-2.5, typically white, gray, green or red in color, a specific gravity of 2.53. Its streak is white.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P n c n |
| Cell (Å, °) | a = 13.2608, b = 27.0559, c = 5.2671; α = 90, β = 90, γ = 90 |
| Cell volume | 1889.74 ų, Z = 4 |
| Axial ratios | 0.4901:1:0.1947calculated from COD 9014278 |
| Source structure | COD 9014278 (American Mineralogist, 2011) — 1 of 12 structures |
Physical properties
| Density (calculated) | 1.968 g/cm³calculated from COD 9014278 |
|---|---|
| Hardness (Mohs) | 2.25single sourceWikidata (CC0) 2single sourceWikidata (CC0) 2-2.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.53 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | gray, green, red, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) |
Chemistry (calculated)
| Molecular weight | 647.83 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mg 15.01%, Si 26.01%, O 56.8%, H 2.18% |
Classification
| Nickel-Strunz (10th) | 9.EE.25Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.EE.25Wikidata (CC0) |