The siliceous diatom frustule has the highest strength of any known biological material. (en)
Transparent glass test or shell of a radiolarian (en)
Sponge spicules, like this from a siliceous glass sponge, form structures many times more flexible than equivalent structures made of pure silica. (en)
Magnetosome chain with octahedral habits modelled lower right (en)
Magnetotactic bacterium containing a chain of magnetosomes (en)