I found several hand-size shells on a Baja beach last winter, and learned they’re called pen shells. I would have named the translucent beauties fan shells, since they look like fluted fans decorated ...

It's bendy but brittle, visible but hidden, a silk weaver capable of producing a rare black pearl. Though this cross-trained mollusk sounds like some exotic gem of far-off shores, it's actually quite ...

The Noble Pen Shell, part of the Pinnidae family, is found in the Mediterranean Sea and is the largest of all pen shells, reaching up to 4 feet in size. This shell is known for its beautiful copper ...

The endangered Mediterranean mollusk Pinna nobilis, pictured in Spain. The golden silk, a luxury once reserved for Roman emperors, has been recreated by modern scientists. In a study published in ...