Fossil stromatolite slab, polished on one side .
Numerous small pyrite crystals scattered through this specimen.
Alcheringa narrina from the Archaean Meentheena Member within the Tumbiana Formation.
Age is approx. 2.7 billion years.
From near Nullagine in Western Australia.
Approx. 130 mm x 90 mm x 13 mm thick at widest points.