tortoiseshell, horny, translucent, mottled plates covering the carapace of the tropical hawksbill turtle. The plates, too thin for most purposes in their original form, are usually built up in layers that are molded or compressed after the surfaces have been liquefied by heat; thus, a firm union is effected after resolidification. Inlays can be imbedded in the shell with a hot iron. Tortoiseshell has been used in veneering since ancient times; its chief use today is in the manufacture of toilet articles and decorative objects. It is imitated in products of celluloid and horn, but the laminated structure of most genuine work aids in identifying the real shell.