Enameloid
The hard, glossy, highly mineralized outer cap of a shark tooth — analogous to mammalian enamel but structurally distinct. It gives the blade its sheen and durability.
Enameloid is the hard, shiny, highly mineralized outer layer that caps a shark tooth's blade. It is analogous to the enamel on a mammal's tooth but forms differently and is structurally distinct, so specialists use the separate term.
Because it is almost entirely mineral to begin with, enameloid survives fossilization well and keeps a natural patina and sheen — one of the marks of a genuine tooth. Beneath it lies the softer dentine.