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.
Russia, Irkutsk region, valley of the Big Chanchik creek. Carbon-containing sandstones with pyrite phenocrysts. Angarskaya series, upper pack. Mesoproterozoic.