While in Charleston, South Carolina USA we stayed at Folly Beach (August 2017). During beach time, I tried to find shark teeth, phosphate fossils and shells. Luckily, I found some the the state's official shell, the Oliva sayana aka lettered olive snail. Dr. Edmund Ravenel (1797-1871) named it this due to the patterns found shells reminded him of hieroglyphic symbols. The dark shell in the image might be a Pliocene fossil.