We learn from Zenothemis that in his time these stones were not held by the people of India in any high esteem, although they are found there of so large a size as to admit of the hilts of swords being made of them. It is well known, too, that in that country they are exposed to view by the mountain-streams, and that in our part of the world they were formerly valued from the fact that they are nearly the only ones[3066] among the engraved precious stones that do not bring away the wax when an impression is made. The consequence is, that our example has at last taught the people of India to set a value upon them, and the lower classes there now pierce them even, to wear them as ornaments for the neck; the great proof, in fact, at the present day, of a sardonyx being of Indian origin. Those of Arabia are remarkable for their marginal line of brilliant white, of considerable breadth, and not glistening in hollow fissures in the stone or upon the sides, but shining upon the very surface, at the margin, and supported by a ground intensely black beneath. In the stones of India, this ground is like wax in colour,[3067] or else like cornel, with a circle also of white around it. In some of these stones, too, there is a play of colours like those of the rainbow, while the surface is redder even than the shell of the sea-locust.[3068] Those stones which are like honey in appearance, or of a fæculent[3069] colour—such being the name given to one defect in them—are generally disapproved of. They are rejected also when the white zone blends itself with the other colours, and its limits are not definitely marked; or if, in like manner, it is irregularly intersected by any other colour; it being looked upon as an imperfection if the regularity of any one of the colours is interrupted by the interposition of another. The sardonyx of Armenia is held in some esteem, but the zone round it is of a pallid hue. CHAP. 24.—ONYX: THE SEVERAL VARIETIES OF IT.