This beautiful 10k ring with a mint green gemstone fluoresces like uranium glass under a black light. However, the hardness of the stone is that of a topaz or spinel gemstone, not glass. We believe the gemstone to be mint green topaz, possibly created. The gemstone measures 7.5 x 9.5 mm. The setting in front measures 13.5 x 15 mm. The ring narrows to 1.5 mm in back. Size 6.75 ring size. Marked 10k, and signed H in a circle. The ring weighs 2.95 grams. A very pretty and interesting ring. Gently pre-owned. Excellent vintage condition.