fornacite

/F AO1 R N AE1 S AY1 T/
noun
  1. 1

    (mineralogy) A rare monoclinic-prismatic lead copper chromate arsenate hydroxide mineral, which is generally green to yellow and translucent to transparent, and has a Mohs hardness of 2.3, a specific gravity of 6.27, and a Strunz classification of 7.FC.10.