MICA

(Lat mico, I shine.) A mineral generally found in thin clastic lamina;, soft, smooth, and of various colours and degrees of transparency. Silica, alumina, potash, and iron nre its principal components. It is one of the constituents of granite. In some parts of Siberia and elsewhere it forms an article of trade, often known under the ■ iiry (rlaSS. [s. 757]