Fossilized Lake Michigan Septarian Rock Lightning Stone 2" x 3"--"Sad Face"

Description

Fossilized Lake Michigan Septarian Rock Lightning Stone 2" x 3"--"Sad Face"
Great specimen and thousands of years old.
Found along a SW Lake Michigan beach, one of the few places in the world where they can be found.
History of Lake Michigan Septarian rocks:
"Lake Michigan Septarian is found on the beaches of the lower west side of Michigan. Consists of clay cemented onto an iron mineral called siderite. These concretions form in part through bacterial activity. They become fractured and the fractures fill with calcite brought in by ground water. The result forms lightning like patterns on a dark background".