Forsterite from the Itkul Hyperbasite Massif, Southern Urals; or, Once Again about Glinkite

The mineralogy of olivine veins from the Itkul hyperbasite massif, Southern Urals, has been studied. These veins are composed of forsterite with minor talc, magnetite, and magnesite. Itkul olivine, which was first described in 1847 as a new mineral—glinkite—is forsterite with a fayalite content of 16.5%. It has been established that the metasomatic olivinites of these veins were formed due to recrystallization of host serpentinite under the influence of a nearby granite intrusion. It is suggested that, because of the visual similarity of Itkul forsterite with Ural demantoid, the latter were for a long time called “chrysolites” or “Ural chrysolites.”