Tetrahedrite \Tet`ra*he"drite\, n. [So called because the
crystals of the species are commonly tetrahedrons.] (Min.)
A sulphide of antimony and copper, with small quantities of
other metals. It is a very common ore of copper, and some
varieties yield a considerable presentage of silver. Called
also {gray copper ore}, {fahlore}, and {panabase}.
[1913 Webster]