08/22/2025
Shark teeth aren’t the only fossils to keep an eye out for! This specimen is an upper premolar from an Ice-Age horse (Equus sp.), probably the second premolar, suggested by its compact, triangular chewing surface and simpler crown compared to the rear molars.
What gives it that “fossil shine”?
That glossy luster is a hallmark of mineralization. After burial, groundwater carries dissolved minerals into the tooth. Two processes do most of the work:
• Permineralization: minerals (often silica or calcite) infill tiny pores and voids, making the tooth denser and heavier.
• Replacement & recrystallization: original tooth material—mostly apatite (a calcium phosphate)—is partially replaced or reorganized into more stable, fine-grained crystals.
Because enamel and dentin are already phosphate-rich, they preserve well. Over thousands of years, wave action and sand abrasion then lightly polish the hardened surface, producing that tell-tale, glassy sheen you also see on fossil shark teeth.
Why the dark color?
Colors range from jet black to brown or tan depending on the surrounding sediments. Iron and manganese oxides commonly stain the fossil; in phosphate-rich settings, darker tones are typical.
Field tips
• Look for luster: that smooth, glassy gleam—especially when wet—is a strong clue you’re holding a fossil, not modern bone or shell.
• Heft and feel: fossil teeth are usually denser and feel “stone-like.”
• Edges and patterns: even when worn, you can often make out the tooth’s biting surface and enamel boundaries.
If you spot that shine while beachcombing, it’s worth a closer look at home, you never know what treasure you might have found!
