Ammophobia

Ammophobia or ammosophobia (from Greek ammos, "sand") is the fear of walking on. Sufferers would walk on the beach, desert floor, and even stepping on the sand in the beachbox. The most common cause of ammophobia is getting sank in the quicksand or seeing on the news that someone was sunk and suffocated by quicksand. The less common cause could be getting stabbed by sand particles when walking on it barefooted, or seeing the footprint imprinted on it gave them dread.