Blue Opal Sphere (with stand) ce809202592053e9621b108fbc302a10 They then entered North America

They then entered North America ~20 million years ago by means of the Bering Isthmus which was once a land mass connection between North America and Asia

Each strand measures 15 inches in length

In 2007 it was reported that a live clam was caught off the coast of Iceland and was determined by researchers at Bangor University to be at least 405 years old

considered to be closely related to today's snakes and similar in shape to today's monitor lizard

dying off and then eventually transforming it into stone

Blue Opal Sphere (with stand) ce809202592053e9621b108fbc302a10 They then entered North AmericaOpal is composed of hydrated silica. It is an amorphous silicate, meaning it does not form crystals. Opals are structurally composed of tiny spheres of silica which, when arranged in perfect geometry, create the famous play of color associated with the stones. The symmetrical arrangement of silica balls acts like a prism, which allows the rainbow spectrum of colors to be visible to the naked eye.