Title: Mercuric Sulfide, Black

CAS Registry Number: 1344-48-5

Additional Names: Ethiops mineral

Molecular Formula: HgS

Molecular Weight: 232.66

Percent Composition: Hg 86.22%, S 13.78%

Literature References: Occurs as a mineral in California. Prepd by passing hydrogen sulfide through a soln of mercuric chloride in hydrochloric acid.

Properties: Black or grayish-black, heavy, odorless, tasteless, amorphous powder. Also occurs as black, cubic crystals (b-form). Transition temp (red to black) 386°. Black form can exist indefinitely in metastable state at room temp. Insol in water, alcohol, dil mineral acids.

Use: As pigment for horn, rubber, etc.