- Marine snails (limpets) have teeth made of the strongest natural material, surpassing spider silk in strength.
- The teeth are composed of goethite nanofibers in a protein matrix, tested to be about five times stronger than most spider silk.
- While not surpassing man-made materials like graphene, the snail teeth outperform Kevlar and match high-quality carbon fibers.
- The article distinguishes between tensile strength (resistance to pulling apart) and hardness (resistance to scratching), noting that wurtzite boron nitrate and lonsdaleite excel in hardness.