Here is a nice buckle size cabochon of Royal Sahara Jasper from Africa. It fits in a belt buckle blank for me just fine and I would consider this a natural freeform cabochon. As I cut it not only to fit a buckle but it kept the natural shape of the nodule and pattern was captured really well. It is a flat cabochon with a bit of natural rind on the back side sloped inside. This rind will not prevent a bezel setting or finding for a buckle. Polished on both sides.
Visit my Sold cabochon Gallery to see past opals I have cut. You will find other examples of materials, shapes, sizes, colors, and in general see my work there. Some stones date back over 15 years in there. I don’t show everything I cut, just the ones I really liked over the years. Please let me know if you have any questions about those materials.
Its also important to visit your local rockclub if you have one near by. Its a
great place to start if you are new to gems and minerals. Thank you.