This stone, in consequence of its extraordinary beauty, has been called “pæderos”[3059] by many authors; and some who make a distinct species of it, say that it is the same as the stone that in India is called “sangenon.” These last-mentioned stones, it is said, are found in Egypt also, Arabia, and, of very inferior quality, in Pontus. Galatia, too, is said to produce them, as also Thasos and Cyprus. The finest in quality of them have all the beauty of opal, but they are of a softer brilliancy, and are mostly rough on the surface. Their colour is a mixture of sky-blue and purple, and the green hues of the smaragdus are wanting: those, too, are preferred, which have their brilliancy deepened by a vinous hue, rather than those which have their colours diluted, as it were, with water. CHAP. 23.—SARDONYX; THE SEVERAL VARIETIES OF IT. DEFECTS IN THE SARDONYX. Thus far we have spoken in reference to the stones, which, it is generally agreed, belong to the highest rank; in obedience, more particularly, to a decree[3060] that has been passed by the ladies to that effect. There is less certainty with respect to those upon which the men as well have been left to form a judgment; seeing that the value of each stone depends more particularly upon the caprice of the individual and the rivalry that exists in reference thereto; as, for example, when Claudius Cæsar was so much in the habit of wearing the smaragdus and the sardonyx.[3061] The first Roman who wore a sardonyx, according to Demostratus, was the elder Africanus, since whose time this stone has been held in very high esteem at Rome: for which reason, we shall give it the next place after the opal. By sardonyx, as the name[3062] itself indicates, was formerly understood a sarda with a white ground beneath it, like the flesh beneath the human finger-nail; both parts of the stone being equally transparent. Such, according to Ismenias, Demostratus, Zenothemis, and Sotacus, is the sardonyx of India; the last two giving the name of “blind” sardonyx to all the other stones of this class which are not transparent, and which have now entirely appropriated the name to themselves. For, at the present day, the Arabian sardonyx presents no traces whatever of the Indian sarda,[3063] it being a stone that has been found to be characterized by several different colours of late; black or azure for the base, and vermilion, surrounded with a line of rich white, for the upper part, not without a certain glimpse[3064] of purple as the white passes into the red.[3065]