I've sold Moonstone before and it doesn't have the same type of glow that a Moonstone has. I had a gallery gift shop for 10 years before I had to close and this ring was purchased through a dealer as opal. It doesn't have the many colors like many opals do but not all do. I recently sold some Moonstone Earrings so I know how they shine. They have more movement in the shine when you turn them.