D defs.my
Entry 1 sense Webster, 1913

Proustite

· Proust·ite · IPA
01 n. A sulphide of arsenic and silver of a beautiful cochineal-red color, occurring in rhombohedral crystals, and also massive; ruby silver.
  1. 1.
    A sulphide of arsenic and silver of a beautiful cochineal-red color, occurring in rhombohedral crystals, and also massive; ruby silver.(Min.)