tor·toise shell | ˈtȯr-təs shel
A mottled, nutty brown shell material with a spotted, striped, or sometimes even speckled pattern
Tortoise shell is popular for jewelry and hair combs, but was banned and is no longer used for these items. Currently, those items are made from very close plastic imitations of tortoiseshell.
One technique to differentiate tortoiseshell from its imitators is to touch the surface with a hot pinpoint. A tortoise will give off a smell like burning hair while plastic will emit an acrid, chemical odor.