Mollusks maintain the symmetry of their pearls by adjusting the thickness of each layer of shimmering nacre. If one layer of the pearl’s nacre is thinner, the next layer is thicker and will balance ...

Pearls form as a natural defense mechanism when oysters trap irritants inside their shells and coat them with layers of nacre. While natural pearls are rare, cultured pearls are carefully farmed using ...

Learn about how mollusks create these shiny gems and how that biological process could change as Earth’s waters warm Abigail Eisenstadt Smooth pearls in the shape of orbs and ovals are usually created ...