Keilite
Iron-magnesium sulfide mineral
From Wikipedia, the free encyclopedia
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]
| Keilite | |
|---|---|
| General | |
| Category | Sulfides |
| Formula | (Fe2+,Mg)S |
| IMA symbol | Ke[1] |
| 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.[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]
