Figure 1. This giant clam pearl was recovered from a huge Tridacna gigas mollusk in Papua New Guinea. Photo by Lai Tai-An Gem Lab. Natural pearls from various clam species are not as rare as many ...

What's inside a clam? A retractable foot, a siphon for sucking up water, powerful muscles, and, sometimes, a pearl. And you thought oysters were fancy. Following is the transcript of the video.

Pearls were found in the clams in many rivers, but none of any particular value was found except in Sugar and Pecatonica Rivers, in Southern Wisconsin. Not only has the stock of pearls been ...