_It is usually found in rounded pieces, but is sometimes crystallized in compressed six─sided prisms, and in double six─sided pyramids._ So little is this gem in request in Europe, that it is seldom to be found in the possession of jewellers; but in Brazil it is considered inferior only to the diamond. It is usually procured from South America; yet it occurs in Saxony; and, with the ruby and sapphire, amongst sand in the rivers of Ceylon. Such is the hardness of the chrysoberyl, that, when properly polished, which is a difficult operation, it is capable of receiving a lustre nearly equal to that of the diamond. We are informed that, a few years ago, a considerable number of these gems were imported into this country from Brazil, but that the greater part of them were entirely spoiled by inferior workmen, and that the rest were so ill─cut that they remained unnoticed, and without value. The smaller stones are said to appear to most advantage in circular ear─drops; and the larger specimens form necklaces and ring stones of great beauty. The variety which exhibits an opalescent appearance, or presents a bluish light, undulating as it were in the interior of the stone, and changing its situation according to the position of the observer, is chiefly valuable as an article of curiosity: the transparent kind is always preferred by the jeweller. SCHORL FAMILY. 61. _The TOPAZ is a gem usually of a wine─yellow colour, but sometimes orange, pink, blue, and even colourless, like rock_ _crystal; of a lamellar or foliated structure, harder than quartz, but not so hard as ruby._ _It varies considerably in its crystallization; is 3½ times heavier than water; and, when placed upon any object, shows a double image of it._ The name of topaz is derived from an island in the Red Sea, where the ancients found a stone, but very different from ours, which they denominated topaz. The best topazes are of a deep colour, and are imported from Brazil; the most brilliant ones are supposed to be those of Saxony; but the latter are generally of very pale colour. This species of gem is found in many parts of Europe, but defective in transparency, and sometimes even opaque. It occurs in large crystals, and rolled masses, in an alluvial soil (269), in the upper parts of Aberdeenshire, Scotland; and in veins, along with tin─stone, at St. Anne’s, in Cornwall. Topazes, more than a pound in weight, have been found in Scotland. Mr. Mawe speaks of a topaz mine at Capon, near Villa Rica, in Brazil. In two breaks or slips of the rocks, he says, there were little soft places where the negroes found the topazes by scraping in them with pieces of iron. He himself observed at least a cart─load of inferior topazes, any number of which he might have taken away; but all that he saw were defective and full of flaws.