koerzivite

Koerzivite is a rare mineral composed of niobium, titanium, and oxygen. Its chemical formula is often represented as (Nb,Ti)O2, though it can incorporate other elements such as iron and tantalum in solid solution. The mineral was first discovered in the Khibiny Massif on the Kola Peninsula in Russia, a region known for its unusual mineralogy. Koerzivite typically occurs as small, prismatic crystals, often found in association with other niobium-bearing minerals like pyrochlore and loparite. The crystals are usually dark in color, ranging from black to dark brown, and possess a vitreous to greasy luster. Its hardness on the Mohs scale is typically between 5 and 6, indicating a moderately hard mineral. Koerzivite is not a significant ore mineral for niobium or titanium due to its rarity and small crystal size, but it is of scientific interest for understanding the complex geological processes that lead to the formation of rare earth and niobium-rich deposits. Its optical properties, including its refractive indices and birefringence, have been studied to help characterize its mineral structure and composition.