korterite

Korterite is a rare mineral discovered in 1971 in the Koryak Mountains of Russia. It is named after the Russian mineralogist, Boris Petrovich Korter, who first identified and described the mineral. Korterite is a complex oxide mineral with the chemical formula (Na,Ca)2(Fe,Mn)3+O(SiO4). It typically occurs as dark brown to black prismatic crystals or granular masses in association with other minerals such as magnetite, hematite, and quartz.

Korterite is classified as a nesosilicate, meaning it contains isolated silica tetrahedra. It crystallizes in the monoclinic system and has a hardness of approximately 5.5 on the Mohs scale. The mineral is opaque with a submetallic to metallic luster and has a black streak. It is weakly magnetic due to the presence of iron and manganese.

The type locality for korterite is the Koryak Mountains, where it was found in association with other rare minerals such as kornerupine and shcherbakovite. Korterite has also been reported from other locations, including the Kola Peninsula in Russia and the Ilimaussaq complex in Greenland. Despite its rarity, korterite is of interest to mineralogists due to its unique chemical composition and the geological conditions under which it forms.