This is an exceptional example the earths earliest life forms, from an unusual South American Precambrian formation. This slab of stromatolite was cut and polished perpendicular to the individual colonial layers and thus exhibits multiple colored growth rings. The stromatolite has been polished to a mirror finish. The age of this stromatolite is estimatesd to be 2.4 to 2.6 BILLION yrs old, from a time in the Precambrian when stromatolite was believed to be both unbiquitous and abundant on earth. This remarkable specimen is appropriate for display, teaching or research, representing primitive bacterial life responible for forming the atmosphere that we breath today. This specimen is a must for the serious stromatolite collector.