D defs.my
Entry 1 sense Webster, 1913

Orpiment

/ôr'-pəm-ənt/ · Or·pi·ment · IPA /ˈɔɹpəmənt/
01 n. Arsenic sesquisulphide, produced artificially as an amorphous lemon-yellow powder, and occurring naturally as a yellow crystalline mineral;…
  1. 1.
    Arsenic sesquisulphide, produced artificially as an amorphous lemon-yellow powder, and occurring naturally as a yellow crystalline mineral; -- formerly called auripigment. It is used in king's yellow, in white Indian fire, and in certain technical processes, as indigo printing.(Chem.) Also: auripigment
    “Our orpiment and sublimed mercurie.” Chaucer.
Phrases & compounds
Red orpiment — realgar; the red sulphide of arsenic.
Yellow orpiment — king's yellow.