214                 NATURAL HISTORY OF GEMS.
	sidered as especially adapted for the preservation of the unguenta, or perfumed oils, then so much in use, it was worked up into the little vases called alabastra (or "with­out handles"), and thereby becoming known as the alabas­trites, or " unguent-jar stone," lost its original désignation of Onyx, which thenceforward came to be confined to the gem now to be discussed. The first mention of the Onyx as a precious stone occurs in the inscriptions of the Parthenon, dating from the Pelo-ponnesian War (b.c. 431-404), where, amongst the offer­ings is registered " a large Onyx engraved with an ante­lope; weight 33 draehms." Theophrastus ('On Stoues,' 31) uses the diminutive ïíý÷éïí, indicative of its value, and also perhaps to distinguish it from the marble Onyx ; and describes it as made up of white and dark-brown (<£<ûoç) in alternate layers. This ûíí÷éïí of Theophrastus and the early Greeks was not the stone known to the Romans and to lis as the Onyx, or Nicolo (the Italian corruption of Ouijculus), but the gem upon which the best archaic and Etruscan intagli for the most part occur, and which is now commonly called the Tricoloured Agate. This appears from the description above quoted from Theophrastus. His definition of oue of its shades as öáÀïò gives the very epithet Homer frequently applies to spring-water, and therefore can only signify something blackish and at the same time translucent, the actual appearance presented by water deep and clear. Totally inapplicable are these terms to the Onyx of the Romans, our Nicolo, where the layers are opaque, and usually of vivid colours, blue horizontally superimposed upon black; but they exactly describe the appearance of what is universally called by dactylio-graphers the " Tricoloured, or Banded, Agate," that so favourite material with the early Glyptic art, and which the primitive lapidaries invariably cut across the strata, so as to