Precambrian Stromatolite Collenia undosa

This slab of stromatolite was cut and polished perpendicular to the individual finger-like colonies. The stromatolites are preserved in a red agate and both sides of the slice have been polished to a mirror finish. Note the detail of the laminae in each small digitate colony. The age of this stromatolite is estimatesd to be 2.2 to 2.4 billion years old, from a time in the Precambrian when stromatolite was believed to be both unbiquitous and abundant on earth.