THE classical theory of the mechanism of production of the carbonate fraction of the calcium carbonate of the hen's egg shell is that of Gutowska and Mitchell 1. This theory makes use of the ...

However, for the individual that concealed itself in the oyster that is now in the Museum's collections, getting out of its hiding spot turned out to be as deadly as the predator it may have been ...

As the oyster grows, its shell must expand. This growth is facilitated by the mantle, a thin tissue layer that secretes calcium carbonate and organic proteins to build the shell. Pearls form when a ...

You won’t get pearls from Pacific oysters or other species raised for food. Pearls are actually calcium carbonate spheres grown by some species. When an oyster shell breaks or is no longer going to be ...

Pearls are made by marine oysters and freshwater mussels as a natural defence against an irritant such as a parasite entering their shell or damage to their fragile body. The oyster or mussel slowly ...