mercuric sulfide

or mercury sulfide

noun Chemistry.

a crystalline, water-insoluble, poisonous compound, HgS, occurring as a coarse, black powder (black mercuric sulfide) or as a fine, bright-scarlet powder (red mercuric sulfide): used chiefly as a pigment and as a source of the free metal.

Origin of mercuric sulfide

First recorded in 1850–55

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018