This ancient 2.0 billion year old stromatolite is from Australia. Pilbaria perplexa believed to have grown in a shallow marine lagoon environment with rare periods of emergence. The environment has also been conjectured to have resemble the hot-spring environment of the North American Yellowstone National Park -- it is thus easy to speculate that its origins are the Archaea as opposed to prokaryotic cyanobacteria (or possibly both), but we will probably never know.

This stromatolite is unlike any I have seen and rather resembles leopard skin in color and pattern with apparent dark regions being the result of branching colonies. Note the size, very large making the natural beauty even more awesome. For sure, the camera fails to capture the beauty of this very hard to obtain stromatolite that has been nicely polished.