Teallite
Teallite is a rare sulfide mineral with the chemical formula PbSnS2. It is a lead tin sulfide and is part of the herzenbergite group.
Properties: Teallite typically occurs as flexible, thin, metallic grey orthorhombic crystals, often with a layered or flaky appearance. It exhibits perfect cleavage parallel to the basal plane, giving it a micaceous habit. Its hardness is quite low, ranging from 1.5 to 2 on the Mohs scale. The mineral has a metallic luster and a dark grey streak.
Occurrence: Teallite is found in hydrothermal veins, typically associated with other sulfide minerals such as galena, sphalerite, and stannite. It's a relatively uncommon mineral, with notable occurrences in Bolivia (particularly the type locality at the Santa Fé mine), Argentina, and Japan.
Etymology and History: Teallite was first described in 1904 from specimens found in the Santa Fé mine in Bolivia. It is named in honor of Sir Jethro Justinian Harris Teall (1849–1924), a British geologist and petrologist.
Uses: Due to its rarity and limited occurrence, teallite has no significant industrial uses. It is primarily a mineral of interest to collectors and researchers.
Distinguishing Features: Teallite can be distinguished from similar minerals by its lead and tin content, its perfect cleavage, and its association with other sulfide minerals. X-ray diffraction analysis is often required for definitive identification.