Marcasite is a ferrous disulfide, FeS2, its older name is lanceolate kyz. It was named in 1845 by Wilhelm Karl von Haidinger after the Arabic name for pyrite and similar minerals. It is formed in sedimentary rocks, on ore veins, its occurrence is often in brown coal, where it occurs in concretions and well-developed crystals. The crystals are lanceolate, pyramidal, tabular, prismatic, often forming crested entanglements. They also form granular, solid or radially radiate aggregates with a renal surface. The color is brassy yellow, pale yellow, it weatheres quickly in the air More info
Marcasite is a ferrous disulfide, FeS2, its older name is lanceolate kyz. It was named in 1845 by Wilhelm Karl von Haidinger after the Arabic name for pyrite and similar minerals. It is formed in sedimentary rocks, on ore veins, its occurrence is often in brown coal, where it occurs in concretions and well-developed crystals. The crystals are lanceolate, pyramidal, tabular, prismatic, often forming crested entanglements. They also form granular, solid or radially radiate aggregates with a renal surface. The color is brassy yellow, pale yellow, it weatheres quickly in the air