Chalcopyrite

Formula: CuFeS2 Tetragonal Description: Chalcopyrite is an important ore of copper found in a wide range of hydrothermal environments. It is often associated with sphalerite and galena. It oxidizes to form copper minerals such as malachite, azurite, …

Dyscrasite

Formula: Ag3Sb Orthorhombic Description:Dyscrasite as a rare mineral found with other silver minerals in hydrothermal deposits. ONEIDA COUNTY: Dyscrasite occurs with silver, gold, pyrargyrite, acanthite, galena, sphalerite and chalcopyrite in the Lynn massive sulfide deposits (Kennedy …

Acanthite

Formula: Ag2S Monoclinic Description: Acanthite is a low-temperature hydrothermal mineral. It can form from inversion of argentite, a mineral that forms in higher temperature hydrothermal deposits. ONEIDA COUNTY: Acanthite occurs with gold, silver and other silver minerals …

Chlorite Group

Formula: (Al, Fe, Li, Mg, MN, Ni, Zn)6 (Si, Al)4O10(OH, O)2 MONOCLINIC or TRICLINIC Description: Chlorite represents a group of over 10 minerals related by complex solid solution substitutions. These minerals are generally fine-grained, micaceous and dark green. …

Gold

Formula: Au Isometric Description:Gold is usually found in hydrothermal deposits where it forms at a wide range of temperatures and geological settings. Gold may form in exhalative deposits formed on the sea floor associated with Archean …

Pyrargyrite

Formula: Ag3SbS3 Hexagonal Description: Pyrargyrite is a deep red to nearly black mineral found in hydrothermal veins often associated with other silver minerals, galena, pyrite and quartz. ONEIDA COUNTY: Pyrargyrite occurs at the Lynn massive sulfide deposit, in …

Sphalerite

Formula: ZnS Isometric Description: Banded sphalerite, near Hazel Green in Lafayette County, Wisconsin. Sample is about 1 cm long. Sphalerite occurs in a wide range of hydrothermal environments. It is common with chalcopyrite in exhalative massive …

Hydromagnesite

Formula: Mg5(CO3)4(OH)2.4H2O Monoclinic Description: Hydromagnesite forms white chalky masses or, occasionally sprays of radiating acicular to bladed crystals due to the alteration and weathering of magnesium-rich rocks. CRAWFORD COUNTY: Hydromagnesite is a major component of moon-milk …