Good morning, this item is cross posted on Facebook. This cool rock was found in the surf at Onslow Beach in Jacksonville NC. There are Gastropods, unidentified shell and mystery circles/ovals by the hundreds if not thousands. My question is what are these little round areas? The rock is shown wet in order to bring out the features listed. Size 1.5” x 1”. The rock is smooth to touch despite seeing texture in photo. Thank you in advance!