Keilite
Keilite is an iron-magnesium sulfide mineral with the chemical formula (Fe,Mg)S) that is found in enstatite chondrites.[1] Keilite is the iron-dominant analog of niningerite.[2][3] Keilite is named after Klaus Keil (born 1934).[2]
| Keilite | |
|---|---|
| General | |
| Category | Sulfides |
| Formula (repeating unit) | (Fe2+,Mg)S |
| Strunz classification | 2/C.15-15 |
| Dana classification | 2.8.1.9 |
| Crystal system | Isometric |
| Crystal class | Hexoctahedral |
| Space group | Fm3m (No. 225) |
| Unit cell | a=5.1717(18)Å |
| Identification | |
| Formula mass | 81.91 gm |
| Colour | Grey |
| Crystal habit | Microscopic crystals |
| Cleavage | Distinct/Good |
| Tenacity | Brittle |
| Luster | Metallic |
| Diaphaneity | Opaque |
| Specific gravity | 3.958 |
| Density | 3.958 |
Occurrences
Examples of keilite occurrences are enstatite chondrites and the Zakłodzie meteorite.[3] It appears to be confined to impact-melt influenced enstatite chondrites that were quenched. There are also some meteorites interpreted as impact-melt breccias that don't contain keilite. This is explained as a deeper burial after impact, which slowed cooling and enabled retrograde reactions (diapthoresis) to take place.[4]
References
- "Keilite Mineral Data". WebMineral. Retrieved 15 February 2021.
- "Keilite" (PDF). Handbook of Mineralogy. Retrieved 15 February 2021.
- Shimizu M, Yoshida H, and Mandarino JA. "The New Mineral Species Keilite, (Fe,Mg)S, The Iron-Dominant Analogue of Niningerite" (PDF). The Canadian Mineralogist. 40: 1687–1692.CS1 maint: multiple names: authors list (link)
- Keil, Klaus (30 April 2007). "Occurrence and origin of keilite, (Fe>0.5,Mg<0.5)S, in enstatite chondrite impact-melt rocks and impact-melt breccias". Chemie der Erde - Geochemistry. 67 (1): 37–54. doi:10.1016/j.chemer.2006.05.002.
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