Schreyerite (V2Ti3O9), is a vanadium, titanium oxide mineral found in the Lasamba Hill, Kwale district in Coast Province, Kenya.
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.
Investigation of deposits of green vanadium-bearing kornerupine, revealed the presence of a new vanadium mineral through observations in reflected light.
With crossed polarizers, moderate anisotropism becomes evident, so that the very fine lamellar twinning becomes distinct.