Chrysoberyl

( βήρυλλος, a beryl). A gem of a yellowish green colour; a species of corundum (q.v.). Chryso-clavus (Lat. golden nail-head ). All rich purple silks, woven or embroidered with the clavus in gold, were so named. They were used for altar frontals, and the clavi were sometimes made so large that a subject was embroidered upon them; they were then called sigillata or sealed . (See Clavus .)