Since the above period, tourmaline has been found in Brazil; and in Norway, Germany, France, and several other parts of Europe. It generally occurs embedded in different kinds of mountain rock; and, in these, is rather confined to single beds or strata, than disseminated through the whole mass of the mountain. A piece of tourmaline, of cylindrical form, and brownish grey colour, was some time ago discovered in the neighbourhood of Kitt─hill, near Callington, Cornwall. Black tourmaline, both in large and small crystals, is found in granite rock, in the vicinity of the Logan, or Rocking─stones, near Treryn, in the same county. When laid on a table, the tourmaline appears a dark and opaque stone; but, when held against the light, it has generally a pale brownish hue. It is sometimes cut, polished, and worn as a gem; but, on account of the muddiness of its colours, it is not in general much esteemed. Those persons who wear tourmalines set in rings consider them more as objects of curiosity than of elegance: they show them as small electrical instruments, which, after being heated a little while by the fire, will attract and repel light bodies. In the superb collection of minerals of the British Museum, there is a magnificent specimen of _red tourmaline_, or _rubellite_, which has been valued at 1000_l._ sterling. It was presented by the King of Ava to the late Colonel Symes, when on an embassy to that country, and was afterwards deposited by the latter in Mr. Greville’s collection; with that collection it became the property of the British Museum. GARNET FAMILY. 70. _The PRECIOUS, or NOBLE GARNET, is a gem of crimson colour, which, when crystallized, has the form of a twelve─sided solid (Pl II, Fig. 11, 12). It is sufficiently hard to scratch quartz, and is about four times as heavy as water._ This stone is found abundantly in many mountains (particularly of primitive rock), in different parts of the world. But garnets of the hardest and best quality are brought from Bohemia, where there are regular mines of them; and a great number of persons are there employed in collecting, cutting, and boring them. The boring is performed by an instrument having a diamond at its extremity, which is rapidly turned by a bow. The work is so expeditiously performed, that an expert artist can bore 150 garnets, or he can cut and polish thirty, in a day. In Suabia there are two towns in which upwards of 140 persons are employed in these operations.