PbAgAsS3

PbAgAsS3 is a ternary mineral species belonging to the sulfosalt group. It is characterized by its specific chemical composition of lead, silver, arsenic, and sulfur. The mineral was first described in 1978 from the Lengenbach quarry in Switzerland. PbAgAsS3 is known by the common name of scottite.

Structurally, scottite is an arsenic sulfosalt, meaning its crystal lattice incorporates arsenic atoms within a framework of sulfur atoms, along with lead and silver. The arrangement of these elements gives it its distinct crystalline properties. It typically occurs as small, dark, prismatic crystals. The color of scottite is usually dark gray to black, with a metallic luster.

Scottite is a relatively rare mineral, found in hydrothermal mineral deposits. Its occurrence is often associated with other sulfosalt minerals. The Lengenbach quarry in Fäld, Binntal, Switzerland, is a notable locality where scottite has been found. Other occurrences have been reported in various mineralized districts globally.

The mineral's physical properties include a Mohs hardness typically in the range of 3 to 3.5, indicating it is relatively soft. Its specific gravity is around 5.9 g/cm³. Due to its rarity and specific geological associations, scottite is of interest to mineralogists and collectors.