Description

Usually contain Mg,Fe,Mn and Zn etc. Trigonal system. As ditrigonal-scalenohedron and rhombic crystals, perfect crtstal is common. Crystal forms are varied, over **0 kind of different aggregation forms. Mainly are granular, tabular and lamellar, form into contact twins and polysynthetic twins. Various aggregation forms as: lamellar (tabular) or fibrous calcite as parallel or approximate parallel intergrowth, is called argentine and bibrous calcite. Also as drusy, tabular, lamellar, granular, stalactitic, coolitic,leguminous, nodular and brtryoidal aggregates. Colorless, white or varicolored by the staining of impurities, as light yellow, light red, purple, brownish-black, green etc. The colorless and transparent variety is called Iceland sapr. Vitreous luster. H2.**3.*5, p 2.**2.9 g/cm3. Occurs in various geologic conditions, widely distributed in three classes of rocks, and is also formed either by hydrothermal or by weathering processes. Primary material for making cement and calcium carbide. Calcite has various forms and varied color stained by other mineral, and always combines with other minerals. So they are nice for enjoying.