Zirkelite
From Wikipedia, the free encyclopedia
| Zirkelite | |
|---|---|
| General | |
| Category | Oxide mineral |
| Formula | (Ti,Ca,Zr)O(2−x) |
| IMA symbol | Zke[1] |
| Strunz classification | 4.DL.05 |
| Crystal system | Isometric |
| Crystal class | Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m) |
| Unit cell | a = 5.02 Å, Z = 4 |
| Identification | |
| Color | Black, reddish brown |
| Crystal habit | Crystalline, metamict, pseudocubic |
| Cleavage | None |
| Fracture | Brittle |
| Luster | Resinous |
| Streak | Brownish grey |
| Diaphaneity | Subtranslucent to opaque[2] |
| Density | 4.7 |
| Other characteristics |  Radioactive |
Zirkelite is an oxide mineral with the chemical formula (Ca,Th,Ce)Zr(Ti,Nb)2O7. It occurs as well-formed fine sized isometric crystals. It is a black, brown or yellow mineral with a hardness of 5.5 and a specific gravity of 4.7.
Zirkelite was first discovered in Brazil in 1895. It was named for German petrographer Ferdinand Zirkel (1838–1912).
