They are several inches long. Look for cracks or joints in the rock. Notice in particular the joints which are more or less parallel with the mountain surface. These are exfoliation joints. They formed as a result of expansion due to release of confining pressure as the pluton that makes up Stone Mountain was uplifted and overlying rocks eroded.
Exfoliation is the dominant process of physical weathering on the mountain.
As these sheets exfoliate, circular to oval depressions, referred to as solution pits, are left beneath them. The pits range in diameter from about 15 cm to a few tens of meters. Look carefully and see if you can locate some of them. The solution pits hold water after a rain, and this water helps to weather the rock. Look in some of these small pits to see what minerals you can identify in the sediment which coats their bottoms.