Fossil stromatolite polished on one side with natural weathered exterior.
Alcheringa narrina from the Archaean Meentheena Member within the Tumbiana Formation.
Age is approx. 2.7 billion years.
From near Nullagine in Western Australia.
Dimensions at widest points approx. 170 mm x 160 mm x 80 mm thick.
Weighs 3,160 grams.