258                 NATURAL HISTORY OF GEMS. necessarily, from the fact to be stated presently, known to the ancients, it was not reckoned a variety of the Ophites, but, as it would seem, olassed amongst the Agates. Its sanguine hue would have caused it to fall under the denomination of the Hœniachates. This with the Green and the Black can justly claim the precedence in antiquity over all the other materials of the Glyptic art. They were almost exclusively employed for the cylinder signets be­longing to the first period of Assyrian art, that is prior to the reign of Sargon (Shalmanesar), and the designs cut upon them are identical in character with the earliest bas-reliefs discovered at Nineveh. The Black is of a parti­cularly fine and uniform texture, so that it commonly passes, in these remains, for actual black Jasper.