The mother-rock is a granitic outcrop measuring roughly 1,000 meters by 600 meters.
The rocks surface is incrusted with small nodules shaped like biconvex discs that are between 2 and 12 cm.
Rain or dew water seeps into the cracks in the mica, and when winter comes it freezes.
It takes many hundred winters for this to happen.
Photo credit:Claudio Franco/Flickr
For the local population, Pedras Parideiras symbolizes fertility.
Scientists have a few theories but the exact origin of these stone eggs is still not known.
There are about 70 eggs still attached to the rock face ready to pop out in a few decades.
