Preisingerite, Covellite, Chalcopyrite, Quartz
Bi3O(AsO4)2(OH), CuS, CuFeS2, SiO2
Locality:
Clara Mine, Rankach valley, Oberwolfach, Wolfach, Black Forest, Baden-Württemberg, Germany
Field of View: 1.96 mm
Chalkopyrite crystals with indigo-blue covellite coatings together with transparent quartz crystals. The two little white aggregates on the chalcoyrite crystal in the upper part of the photo is the mineral preisingerite. There is a little single crystal of preisingerite on top of the group of quartz crystals to the right.Â
Photo: Michael Förch
Covellite (also known as covelline) is a rare copper sulfide mineral. This indigo blue mineral is ubiquitous in copper ores, it is found in limited abundance and is not an important ore of copper itself, although it is well known to mineral collectors.The mineral is associated with chalcocite in zones of secondary enrichment (supergene) of copper sulfide deposits. Commonly found with and as coatings on chalcocite, chalcopyrite, bornite, enargite, pyrite, and other sulfides, it often occurs as pseudomorphic replacements after other minerals. Â
Preisingerite - A rare secondary mineral in the oxidized zone of some arsenic-bearing hydrothermal mineral deposits. Preisingerite is translucent white to grayish white in color.
