Russia, Subpolar Ural, Kozhim river valley. White, light gray marbled limestones. Include microlayers of quartz-mica composition, the content of quartz grains in them sometimes reaches 30–35%. Under the microscope of the rock, a granoblastic structure with relics of an uneven-grained - blastopsammite and blastoaleurite is found; layered, banded texture and consist of a calcite heterogeneous aggregate (70–99%) with intercalations of quartz grains (up to 25%) and microlayers of carbonaceous-chlorite-sericite, muscovite-chlorite composition.
Russia, Irkutsk region, watershed of the rivers Homolkho and Imnyakh, gold deposit "Golets Vysochayshy", north wall of the pit. Carbon quartz-mica schists. The first photo shows quartz veins in the pit wall. Schists contain veins, lenses, and impregnations of pyrite and pyrrhotite.Khomolkhinskaya series. Thickness 650 meters. Paleoproterozoic.