the native carbonate and silicate of zinc, which, though very generally found in the same deposits, differ materially both in their mineralogical and chemical characters. Calamine is generally white or yellow; occasionally, however, it is blue, green, gray, and brown. It varies also from transparent to opaque; has a vitreous lustre; and occurs both crystallized, stalactitic, mamillated, and massive. It is frequently found in veins, associated with blende, and ores of iron and lead. This very useful ore of zinc contains generally from 60 to 70 per cent. of that metal. See MINERALOGY, and Index.