Fossilized Stromatolite Agate - Rectangular Focal Bead

This piece fossilized stromatolite is agatized with vibrant bands of yellow, dark red, golden brown, and brown originated as organic matter. It also contains some clear layers of quartz. It is one of the oldest fossils dating back in the millions to billion year range. It has been cut and drilled by hand, then polished to show the beauty of the various layers. One can imagine the thousands of years that it took to form these layers, first as microbial life, then through the fossilization process. Stromatolites are layered biochemical accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains in biofilms (specifically microbial mats), especially cyanobacteria. An example of these microbial mats can be seen in the many thermal pools in Yellowstone National Park, yet they also appear in many other environments, including some warm water oceans. Stromatolites are some of the earliest fossils ever found. Stromatolites are a major constitu