in natural history, a gem called by the ancients cryolite, as being of a gold colour; its texture foliaceous; its form cubic, parallelopipedal, or prismatic; its specific gravity from 3.46 to 4.56; it loses its colour only in a very strong heat, and of the usual fluxes it yields only to borax and microcosmic salt. According to Bergman, 100 parts of it contain 46 of argill, 39 of filicose earth, 8 of mild calcareous, and 6 of iron. Its great specific gravity shows these earths to be very perfectly united.

The finest topazes in the world are found in the East Indies; but they are very rare there of any great size: the Great Mogul, however, at this time, possesses one which is said to weigh 157 carats, and to be worth more than 20,000 pounds. The topazes of Peru come next after these in beauty and in value. The European are principally found in Silesia and Bohemia, and are generally full of cracks and flaws, and of a brownish yellow.