BBC:
X-ray studies conducted by Jong Seto of the University of
Konstanz and colleagues have identified the structural origin
of sea urchin spines' strength. The spines are made up of two
forms of calcium carbonate: 92% is in calcite crystals, and the
remaining 8% is in a form that lacks any crystal structure. The
amorphous calcium carbonate binds the crystals together the way
mortar binds bricks. The team examined sea urchin samples with
a series of increasingly powerful imaging techniques. They're
now working with international companies and using the sea
urchins' spines as a model to develop a stronger, more
fracture-resistant type of concrete.
