Tooth enamel is harder than steel, but breaks much easier.
Asked by: Ron Pirani, Massachusetts, US
Tooth enamel is mostly hydroxyapatite, which is a mineral form of calcium phosphate. The apatite group of minerals scores a five on the Mohs hardness scale; which makes enamel the hardest biological material.
Tooth enamel is harder than steel, but a lot more brittle. So you can’t scratch your enamel on metal cutlery but you can chip it by trying to open a beer bottle with your teeth.
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Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.
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