CAMÆA, in Natural History, a genus of the semi-pellucid gems, approaching to the onyx structure, being composed of zones, and formed on a crystalline basis: but having their zones very broad and thick, and laid alternately one on another, with no common matter between; usually less transparent, and more debased with earth, than the onyxes.

1. One species of the camæa is the dull-looking onyx, with broad, black, and white zones; and is the camæa of the moderns, and the Arabian onyx. This species is found in Egypt, Arabia, Persia, and the East Indies. 2. Another species of the camæa is the dull broad-zoned, green and white camæa, or the jalpi-camæa of the Italians: it is found in the East Indies, and in some parts of America. 3. The third is the hard camæa, with broad white and chestnut-coloured veins. 4. The hard camæa, with bluish, white, and flesh-coloured broad veins, being the sardonyx of Pliny's time, only brought from the East Indies.