Hawk's eye is tiger's eye before the fire: crocidolite fibers replaced by quartz while still blue-gray, keeping their silky chatoyant sheen. Slate blues ripple across the stone like a raptor's iris. South Africa is the classic source; hardness about 7.Every hawk's eye at GEMIC Institute is natural, certified by our laboratory, and photographed as the exact stone offered. Unique cabochons; worldwide tracked delivery, 30-day inspection period.