Explanation

A carbonate mineral with a simple island like structure. Magnesium, manganese and calcium often replace iron, The varieties of magnesium siderite, manganese siderite and calcium siderite are formed. Triangular system, calcspar (calcite) structure. crystal is rhombohedral and short columnar; Sometimes they form twin according to {0112}: the aggregate is granular, compact and massive or earthy; It is nodular and gel shaped in the sediment. Fresh ones are light gray white, and after weathering, they appear brown or black. glass is glossy, transparent to translucent. The cleavage {1011} is complete. Mohs hardness 4, density 3.7-4.0g/cm3. It acts slowly in cold hydrochloric acid and intensifies in hot hydrochloric acid, generating yellow green FeCl2. It turns orange red under cathode ray. It is mainly formed under hydrothermal and sedimentary conditions. The hydrothermal genesis is vein like, coexisting with sulfide such as ankerite, galena, sphalerite, etc; Sedimentary genesis is layered, occurring in clay rock, shale or coal seam. It can be used as raw mineral material for extracting iron in large amount.

Classification