A cabochon of Wonderstone A was procured to show the nice polish that slabs of this rhyolite from Nevada that could be achieved. George Ingraham, (formerly TaoGems Gemstone Cabochons) was kind enough to offer his service for polishing a cab . George said normally rhyolite can be difficult to polish but he had a treatment he had used in the past on rhyolite and his polished cab shown was superb. The procedure used was to polish up to 14,000 grit, then use Holy Cow polish with vinegar. I sent George several slabs and asked if he would not mind trying tin oxide on one cab and Holy Cow Polish on the other and let me know how the two polishes compared. George sent back both cabs with a nice polish using tin oxide, but a better polish using Holy Cow Polish. Thank you George! We appreciate your time and effort and had not expected to get the cabs also! A source for the Holy Cow Polish with instructions has been found. Check out the web for sources of Holy Cow Polishing Compound. I presume when the polish is mixed as according to the directions with vinegar, it will last a long time for hand polishing special need cabs. Slabs of wonderstone A are sold out at this time, but thanks for your interest!