Melaconite in A Sentence

    1

    Cupric oxide, CuO, occurs in nature as the mineral melaconite (q.v.), and can be obtained as a hygroscopic black powder by the gentle ignition of copper nitrate, carbonate or hydroxide; also by heating the hydroxide.

    2

    Melaconite was formerly largely worked in the Lake Superior region, and is abundant in some of the mines of Tennessee and the Mississippi valley.

    3

    The principal ores of copper are the oxides cuprite and melaconite, the carbonates malachite and chessylite, the basic chloride atacamite, the silicate chrysocolla, the sulphides chalcocite, chalcopyrite, erubescite and tetrahedrite.