Compatible with COE 33 / borosilicate glass
These AAA tumbled black opals have an opaque black base and flash red, blue, yellow, and green. The stones are made from the same top quality material as cabochons, but they are tumbled instead of cut, and the savings are passed on to you! While each batch is different, you can expect 8 to 16 pieces per gram, with each piece being between 3mm and 6mm approx.