Fahlerz

Fahlerz is a collective term used in mineralogy to describe a group of sulfide minerals characterized by a complex, intergrown crystalline structure. These minerals are primarily composed of copper, iron, and sulfur, often with the inclusion of other elements such as zinc, tin, and silver. The name "fahlerz" itself is German, meaning "tetrahedrite" or "fahl ore," reflecting its historical association with these specific mineral species.

The most common members of the fahlerz group include tetrahedrite, tennantite, and sometimes stibnite and helvite. While tetrahedrite typically contains antimony, tennantite contains arsenic, and other variations can occur. They all share a common crystal system, belonging to the cubic crystal family, and often exhibit a metallic luster and a dark gray to black color. These minerals are typically found in hydrothermal veins and ore deposits, often associated with copper, silver, and gold mineralization. Due to their complex composition and intergrowths, precise identification can be challenging and often requires detailed chemical analysis. Fahlerz minerals are considered important sources of copper and can also be a minor source of silver and other valuable metals.