This is a Black agate with a white/tan moss inclusion. It comes from Challis Idaho and can still be found from time to time be locals hunting the area. It is a jet black agate and not translucent at all but opaque. It does have a little transparency in the white area zone of the piece and a tiny bit of red agate peaking through. Nice freeform shape and 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.