This Domical Stromatolite cluster consists out of sandstone and was found on the fossil rich area of Ouarzazate Group, Atlas Mountain, Morocco. It dates from the Proterozoic (600 mya). 

It weights 11.5oz and measures 4 x 2 1/2 x 2 inches. 

Stromatolites are one of the ancients forms of life on Earth and still can be found nowadays growing on shallow warm water.