Here is a matching set of White Tail polished on both sides. Flat cabochon but very nice piece with a little flaw. This is brand new material I discovered near Payson, Arizona and only a few miles from my home. I have tested it with a Refractometer and it does come off as Magnesite. However more tests will be completed in the future to help put a proper Identification on this material.
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.