SPHALERITE, CHALCOPYRITE, MANGANO CALCITE, QUARTZ (small cabinet)

Sphalerite, a sulfide mineral represented by the formula (Zn, Fe)S, serves as the primary source of zinc. This mineral occurs in various types of deposits, predominantly in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide formations. It is commonly found alongside other minerals such as galena, chalcopyrite, pyrite, and various carbonates and silicates, including calcite, dolomite, quartz, rhodochrosite, and fluorite.

Chalcopyrite is a copper iron sulfide mineral and the most abundant copper ore mineral. It possesses the chemical formula CuFeS2 and crystallizes in the tetragonal system. Its appearance ranges from brassy to golden yellow, with a hardness rating of 3.5 to 4 on the Mohs scale. The streak of chalcopyrite is diagnostic, displaying a-tinged black color.

Upon exposure to air, chalcopyrite undergoes tarnishing, resulting in various oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), and digenite (Cu9S5); carbonates such as malachite and azurite; and, less frequently, oxides like cuprite (Cu2O). It is seldom found in association with native copper. Chalcopyrite also serves as a conductor of electricity.

Manganoan calcite, also known as manganocalcite, is a variety of calcite that is rich in manganese, imparting a pink color to the mineral. Its chemical formula is (Ca,Mn)CO3. This mineral was first reported from the Banská Štiavnica Mining District in the Slovak Republic, but it is widely distributed globally, notably found in the Cave of Swords at Naica, Chihuahua,, as well as in Bulgaria.

Manganoan calcite is occasionally mistaken for rhodochrosite. The manganese content in manganoan calcite varies across different localities, and the mineral exhibits a solid solution series between calcite and rhodochrosite, with the color becoming redder as the proportion of manganese increases.