Chemistry:Keilite
From HandWiki
| 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 |
| |re|er}} | Metallic |
| Diaphaneity | Opaque |
| Specific gravity | 3.958 |
| Density | 3.958 |
Keilite is an iron-magnesium sulfide mineral with the chemical formula (Fe,Mg)S) that is found in enstatite chondrites.[2] Keilite is the iron-dominant analog of niningerite.[3][4] Keilite is named after Klaus Keil (born 1934).[3]
Occurrences
Examples of keilite occurrences are enstatite chondrites and the Zakłodzie meteorite.[4] 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 do not contain keilite. This is explained as a deeper burial after impact, which slowed cooling and enabled retrograde reactions (diapthoresis) to take place.[5]
References
- ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
- ↑ "Keilite Mineral Data". http://webmineral.com/data/Keilite.shtml.
- ↑ 3.0 3.1 "Keilite". http://www.handbookofmineralogy.com/pdfs/Keilite.pdf.
- ↑ 4.0 4.1 "The New Mineral Species Keilite, (Fe,Mg)S, The Iron-Dominant Analogue of Niningerite". The Canadian Mineralogist 40 (6): 1687–1692. 2002. doi:10.2113/gscanmin.40.6.1687. https://rruff.info/doclib/cm/vol40/CM40_1687.pdf.
- ↑ 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. Bibcode: 2007ChEG...67...37K.