from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A monoclinic-prismatic dear lead gray mineral containing antimony, arsenic, lead, sulfur, and thallium.
from The Century Dictionary and Cyclopedia
- n. In mineral., a sulphid of arsenic and lead, occurring sparingly in orthorhombic crystals of a lead-gray color in the dolomite of the Binnenthal in Valais, Switzerland. Also called scleroclase.