This rock was found in Florida on the beach on top of the sand. There were no others found. Color of rock is white, the outer rim is clear (see through) the inner layer is solid. The inner layer is smooth. Outer layer is textured. Can not see grains. It is not easy to break. Very hard (diamond: 10). Can not scratch. Heavy for its size. I’m thinking it could have broken off a bigger piece. Would like to know if it is valuable.