Definify.com

Webster 1913 Edition

Noun.

[Gr.

χαλκόσ

brass.]

(Min.)

Native copper sulphide, called also

copper glance

, and

vitreous copper

; a mineral of a black color and metallic luster.

[Formerly written

chalcosine

Chalcocite

chalcocite ‎(countable and uncountable, plural chalcocites)

(mineralogy) Cuprous sulfide, Cu₂S, an important ore of copper.
- 1905, Waldemar Lindgren, The Copper Deposits of the Clifton-Morenci District, Arizona (page 207)
  Their croppings are either entirely barren or contain only a moderate amount of copper, but much richer ore is ordinarily found just above the chalcocite zone.

cuprous sulfide