chalcotrichite

Compact to granular masses also occur, and there are two curious varieties—chalcotrichite and tile-ore—which require special mention.

Chalcotrichite comes from Wheal Phoenix and Fowey Consols mine in Cornwall, and from Morenci in Arizona; tile-ore from Bogoslovsk in the Urals, Atacama in South America, and other localities.

A remarkable case of irregular development is presented by the mineral cuprite, which is often found as well-developed octahedra; but in the variety known as chalcotrichite it occurs as a matted aggregate of delicate hairs, each of which is an individual crystal enormously elongated in the direction of an edge or diagonal of the cube.