A mineral, called also sphalerite, and by miners mock lead, false galena, and black-jack. It is a zinc sulphide, but often contains some iron. Its color is usually yellow, brown, or black, and its luster resinous.
(b)
A general term for some minerals, chiefly metallic sulphides which have a somewhat brilliant but nonmetallic luster.
... the contrary. In that location and over a large stretch of surrounding country-side the earth's outer crust is mainly argillaceous with here and there an outcrop of sandstone. There is not the smallest indication of pitch-blende anywhere in the neighbourhood, and radium, as even those little versed in chemistry or geology are aware, is only to be found in that ... — Men of Affairs • Roland Pertwee
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