Tortoiseshell

Tortoiseshell is a term that refers to two related concepts. Historically, it denotes a material obtained from the shells of certain sea turtles, most notably the hawksbill (Eretmochelys imbricata). The shells were skilled-turned and layered to produce decorative items such as combs, buttons, inlays for musical instruments, and jewelry. The distinctive mottled pattern and warm colors made the material highly desirable in various cultures and time periods.

Because hawksbill turtles are now protected and face significant conservation challenges, international trade in tortoiseshell is heavily regulated. Under CITES and national laws, the sale and export of tortoiseshell from modern productions are largely prohibited or restricted. Some jurisdictions permit limited trade only for pre-existing stock or antique items, subject to documentation and restrictions. In response to conservation concerns, manufacturers and designers increasingly substitute tortoiseshell with synthetic materials such as celluloid, acrylic, or resin that imitate its appearance.

The term tortoiseshell also describes a color pattern seen in animals, most notably cats. Tortoiseshell cats display a mottled coat of black, orange, and cream patches, typically in females due to X-chromosome inactivation patterns. The coloration can vary widely, and males with tortoiseshell patterns are rare and often sterile. The term is sometimes extended to other species and products that exhibit a similar mottled, multicolored appearance.

See also: calico, tortoiseshell coloration, wildlife trade regulations.