Cosalite - Pb₂Bi₂S₅

Habit: Prismatic crystals often Acicular, flexible capillary fibers; commonly massive in aggregates of radiating prismatic, fibrous, or feathery forms.

Environment: In Hydrothermal deposits formed at medium temperatures but also found in contact metasomatic replacements, and epithermal replacements, as well as in Pegmatites

Etymology: For the locality at Cosalá, Mexico