The cat's-eye is a greenish translucent quartz, and when cut _en cabochon_ it presents a moving internal reflection which is ascribed to the presence of filaments of asbestos.

Its perfection is estimated by the natives in proportion to the narrowness and sharpness of the ray and the pure olive-tint of the ground over which it plays.
_Amethysts_ are found in the gneiss, and some discoloured though beautiful specimens in syenite; they are too common to be highly esteemed.

The "Matura Diamonds," which are largely used by the native jewellers, consist of zircon, found in the syenite not only uncoloured, but also of pink and yellow tints, the former passing for rubies.
But one of the prettiest though commonest gems in the island is the "Moon-stone," a variety of pearly adularia presenting chatoyant rays when simply polished.

They are so abundant that the finest specimens may be bought for a few shillings.

These, with _aqua marina_, a bad description of _opal rock crystal_ in extremely large pieces, _tourmaline_, and a number of others of no great value, compose the list of native gems procurable in Ceylon.[1] Diamonds, emeralds, agates, carnelians, opal and turquoise, when they are exhibited by the natives, have all been imported from India.
[Footnote 1: Caswini and some of the Arabian geographers assert that the diamond is found at Adam's Peak; but this is improbable, as there is no formation resembling the _cascalhao_ of Brazil or the diamond conglomerate of Golconda.