Stellerite
Ca4(Si28Al8)O72·28H2OIMA symbol: Steapproved
Stellerite is a silicate mineral with the formula Ca4(Si28Al8)O72·28H2O, crystallizing in the orthorhombic system. It has a Mohs hardness of 3.5-4, typically colorless or yellow in color, with a dull luster, a specific gravity of 2.94. Its streak is white; cleavage is imperfect or perfect.
Photos
Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | A m m a |
| Cell (Å, °) | a = 13.62, b = 17.16, c = 16.68; α = 90, β = 90, γ = 90 |
| Cell volume | 3898.44 ų, Z = 4 |
| Axial ratios | 0.7937:1:0.9720calculated from COD 9005756 |
| Source structure | COD 9005756 (Physics and Chemistry of Minerals, 1978) — 1 of 5 structures |
Physical properties
| Density (calculated) | 1.956 g/cm³calculated from COD 9005756 |
|---|---|
| Hardness (Mohs) | 3.5-4single sourceDana's System, 3rd Appendix (1915) |
| Specific gravity | 2.94 g/cm3single sourceDana's System, 3rd Appendix (1915) |
| Color | colorless, yellowsingle sourceDana's System, 3rd Appendix (1915) |
| Streak | whitesingle sourceWikidata (CC0) |
| Luster | dullDana's System, 3rd Appendix (1915) |
| Cleavage | imperfect, perfectDana's System, 3rd Appendix (1915) |
Chemistry (calculated)
| Molecular weight | 2818.94 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ca 5.69%, Si 27.9%, Al 7.66%, O 56.76%, H 2% |
Classification
| Nickel-Strunz (10th) | 9.GE.15Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.GE.15Wikidata (CC0) |