Schreyerite
| Schreyerite | |
|---|---|
| General | |
| Category | Oxide mineral |
| Formula | V2Ti3O9 |
| IMA symbol | Sry |
| Strunz classification | 4.CB.35 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | C2/c |
| Unit cell | a = 7.06 Å, b = 5.01 Å c = 18.74 Å; β = 119.4°; Z = 4 |
| Identification | |
| Color | Reddish brown; gray in reflected light |
| Crystal habit | As lamellae and microscopic grains, exsolved within rutile crystals |
| Twinning | Polysynthetic, universal |
| Mohs scale hardness | 7 |
| Luster | Metallic |
| Diaphaneity | Opaque |
| Optical properties | Biaxial |
| Refractive index | n = 2.700 |
| Pleochroism | Weak; yellow-brown to reddish brown |
| References | |
Schreyerite (V2Ti3O9), is a vanadium, titanium oxide mineral found in the Lasamba Hill, Kwale district in Coast Province, Kenya. It is polymorphous with kyzylkumite.
The mineral occurs as exsolution lamellae and particles in rutile, coexisting with kyanite, sillimanite, and tourmaline in a highly metamorphosed gneiss. It was named after German mineralogist and petrologist Werner Schreyer, for his research on mineralogy of rock-forming minerals and petrology of metamorphic rocks both in nature and by experiment.