Page:Theophrastus - History of Stones - Hill (1774).djvu/55

  from the Onyx or Alabater Gem, as what we now call only the Onyx was then ometimes called.

The Chernites, or Chermites, was a white Marble, ued in the Sepultures of the ancient Greeks, &c. and about which there have been many Mitakes among the later Authors: thee, as the Species of Marble is now unknown among us, it would be but idle to enquire into.

The Porus was alo a Marble much in Eteem with the Ancients, but unknown to us. Its peculiar Property, as our Author oberves, was its Lightnes. It cut well, and bore a tolerable Polih, and the Statues, &c. made of it, were common in Greece, and called, as thoe of the Parian Marble were called. The Tophus, to which our Author compares this Marble for Lightnes, is a rough Stone of the Pumice Kind, brittle, and eaily crumbling into Powder. It is not much known in England, but common in Germany, where it is ued intead of the Pumice, and called Topfftein and Tugtein. This was a Stone well known among the Greeks, and was what they called the Porus, without any Addition; whereas the other, here decribed among the Marbles by the Author, was called the Porian Marble; from its Reemblance to this Porus. The dark tranparent Stone, next mentioned, was probably of the Obidianus Kind; as well as the Chian. The Antients had two or three of thee dark Marbles, of fine Texture, in great Ue among them. They bore a good Polih, were tranparent in ome Degree when cut into thin Plates, and reflected the Images of Things as our Looking-glaes do: the finet Kind was, for this Reaon, called, which was afterwards written by the Latins, Opianus, Opidianus, and Obidianus. And the true Origin of the Name being forgotten from the fale pelling the Word, After-ages thought it had received it from one Obidius, whom they imagined the firt Finder of it. XVI. There is alo found in the ame Place a tranparent Stone, omething like the Chian: and in others, there are many other Kinds.

XVII. Thee are the Differences which have been mentioned as common to many Stones. But thoe which arie