valentinite

Valentinite is a rare lead–antimony sulfide mineral. It belongs to the sulfosalt group and occurs in hydrothermal ore deposits. The composition is complex and variable; valentinite is typically described as a lead antimony sulfide, with possible substitutions of arsenic for antimony and variable sulfur content. Crystals are metallic to submetallic, usually prismatic or tabular, and have a gray to black color with a metallic luster. The streak is gray to black. It is relatively soft, with a Mohs hardness of about 2.5–3, and has a high specific gravity in the range of roughly 6.0–7.0. Valentinite commonly occurs in association with galena, sphalerite, stibnite, and pyrite, in hydrothermal veins and contact metamorphic zones. It is a rare mineral and has been reported from several localities worldwide.

Because of its composition, valentinite is of interest to researchers studying sulfide mineralogy and ore-formation processes. It is not a major ore mineral for these elements, and because of its rarity, it is mainly collected by mineral enthusiasts and researchers. Handling valentinite should consider potential lead and antimony content.