This is a flat backed semi precious gemstone cabochon. They are domed on top. These are natural stones hand cut in a lapidary shop. We've taken a picture of one piece but due to the nature of the item your going to get variation from piece to piece. Natural stones like black onyx will be quite consistent but many agates and jaspers will very greatly in terms of color and stratification. Of course this is what makes them so unique and attractive.