We must give some account also of onyx,3070 because of the name which it partly shares in common with sardonyx. This name, though in some places3071 given to a marble, is here used to signify a precious stone. Sudines says, that in this stone there is a white portion which resembles the white of the human-finger nail, in addition to the colours of chrysolithos, sarda, and iaspis. According to Zenothemis, there are numerous varieties of the Indian onyx, the fiery-coloured, the black, and the cornel, with white veins encircling them, like an eye as it were, and in some cases running across them obliquely.3072 Sotacus mentions an Arabian onyx, which differs from the rest; that of India, according to him, presenting small flames,3073 each surrounded by one or more white zones; in a manner altogether different from the Indian sardonyx, which presents a series of white specks, while in this case it is one continuous circle. The Arabian onyx, on the other hand, is black, he says, with a white zone encircling it.

Satyrus says, that there is an onyx in India of a flesh colour,3074 partly resembling carbunculus, and partly chrysolithos and amethystos; a variety, however, which he altogether disapproves of. The real onyx, according to him, has numerous veins of variegated colours, interspersed with others of a milk-white hue; the shades of which, as they pass into one another, produce a tint which surpasses all description, and blends itself into one harmonious whole, of a most beautiful appearance.

Not unlike sardonyx, too, is sarda,3075 a stone which also has, in part, a kindred name with it; but before passing on to it, we must first take some notice of all those precious stones which have a brilliancy like that of flame.