Why Shark Teeth Come in So Many Colors
(and Why ID Is Tricky)
Fossil shark teeth can be black, gray, tan, brown, red-orange—even blue-green. The reason isn’t age or species—it’s minerals in the sediment where the tooth fossilized. Groundwater carries dissolved minerals into tiny spaces: iron oxides create orange/red; phosphate and organic carbon yield gray-black; certain clays and trace minerals give blue-green. Pale teeth can reflect minimal replacement or later leaching.
Color is a postcard from the burial environment.
Shark teeth are like puzzle pieces. A shark’s front teeth don’t look exactly like the ones on the sides, and top-jaw teeth can look different from bottom-jaw teeth. As sharks grow and switch snacks, their teeth change shape—some get wider, some get new tiny serrations. Boys and girls can have small differences too, and sometimes a tooth grows a little “weird.” That’s why it’s easy to tell the family a tooth belongs to, but not always the exact species—and that’s totally okay. Science loves a good mystery!
Only have a fragment? Use this quick check:
- Tooth shard: one glossy enamel face; even micro-serrations or a clean knife-edge; dense, non-porous.
- Ray spine shard: a central groove down one side and backward-pointing denticles; no enamel; fibrous texture.
- Bone shard: obvious pores/marrow holes and spongy interior.
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