As a very minor ore of lead and as mineral specimens. It was first described from the famous Langban Mine in Varmland, Sweden where many unique and exotic minerals have been found.
Color is typically white, gray, bluish or yellowish, but can also be red-violet and green.
Luster is greasy to resinous. Crystals are translucent to transparent. Cleavage is poor in several directions, but rarely seen. Fracture is uneven. Streak is white.