Stromatolite Unpolished Stone Slab
This natural rough rock fossil Stromatolite stone slab is 9.75 inches by 6.25 inches and 8 mm thick.
It weighs 1.22 lbs. and is shown wet in the first 2 pictures.
Stromatolites are the oldest known fossils, dating back more than 3 billion years.
Basically Stomatolites are prokaryotes (sort of an ancient cousin to algae) that thrived in warm aquatic environments and built reefs much the same way as coral does today.
They are the oldest living organisms on the planet, and are believed to be the first living organisms on Earth. The name Stromatolite comes from the Greek words that mean bed of rocks.