Sulfosalt mineralSulfosalt minerals are sulfide minerals with the general formula , where A represents a metal such as copper, lead, silver, iron, and rarely mercury, zinc, vanadium B usually represents semi-metal such as arsenic, antimony, bismuth, and rarely germanium, or metals like tin and rarely vanadium X is sulfur or rarely selenium and/or tellurium. The Strunz classification includes the sulfosalts in a sulfides and sulfosalts superclass. A group which have similar appearing formulas are the sulfarsenides (for example cobaltite (Co,Fe)AsS).
CovelliteCovellite (also known as covelline) is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is commonly a secondary mineral in limited abundance and although it is not an important ore of copper itself, it is well known to mineral collectors. The mineral is generally found in zones of secondary enrichment (supergene) of copper sulfide deposits. Commonly found as coatings on chalcocite, chalcopyrite, bornite, enargite, pyrite, and other sulfides, it often occurs as pseudomorphic replacements of other minerals.