▲ 5 r/whatsthisrock
Found near Mt. Diablo in Ca
I was seeing smaller rocks with this design and I thought it was because horse's shoes were scratching the rocks. But then I found this big one and I could see more clearly that the white marks weren't scratches from horses. Is this ancient sea life? Or just a regular rock?
u/Few-Lemon1862 — 14 hours ago