ambergris, waxlike substance originating as a morbid concretion in the intestine of the sperm whale. Lighter than water, it is found floating on tropical seas or cast up on the shore in yellow, gray, black, or variegated masses, usually a few ounces in weight, though pieces weighing several hundred pounds have been found. Ambergris has been greatly valued from earliest times. It is now used as a fixative in perfumes. Its active principle is ambrein, a crystalline alcohol with the empirical formula C₃₀H₅₁OH.

Waxy substance (about 80percnt cholesterol) formed in the intestine of sperm whales, used chiefly as a spice in the East and for fixing the scent of fine perfumes in the West. It is thought to form as a collection of feces around indigestible parts of squid and other prey of the whale. Fresh ambergris is soft, black, and smelly; exposed to sunlight, air, and seawater, it hardens, fades, and develops a pleasant scent. It may wash ashore or be found floating or in the bodies of slaughtered whales. Pieces are usually small, but the largest have weighed almost 1,000 lb (450 kg).

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