Emerald is a precious stone, very green and transparent, in hardness next after the ruby There are two kinds, Oriental and Peruvian. - The oriental is harder, more brilliant, and transparent than the Peruvian; which has generally clouds found in it, and sparkles less. Some, it is said, are found in Cyprus, and even in our own island ; but they are very inconsiderable. - The emerald is supposed to grow more and more pefect in the mine, like the ruby, and to arrive at its greenness by slow degrees. The ancients supposed them of use in medicine, and made amulets of emerald, against all kinds of sorcery; but we have now more experience, or less credulity, and they are valued for their beauty, not for their virtue. Authors mention emeralds of incredible magnitude; of one, pretended to have been seen by Theophrastus in a temple in Egypt, four cubits long, and three broad: and of an obelisk of emerald forty feet high. Emerald consists of silex, alumina, and oxide of iron.