This large, earthy stone is a bit of a mystery. I've had it for ages. The verdict isn't in, but my theory is it is stromatolite. I set it in an asymmetrical, organic manner and attached it to a very substantial box chain.

Dimensions: 1.52" x 1.11"
Length: 20"
Materials: Sterling silver, earthy cabochon
one of a kind

What is stromatolite?
Stromatolites are fossilized layered deposits of algae within ancient sedimentary rock. These old single-celled organisms are believed to be some of the first forms of life on this planet. Some cyanobacteria (algae) in the rock dates back over 3.5 billion years.