What is Moonstone? Moonstone is actually a member of the feldspar mineral group. Feldspar is one of the most prevalent mineral found on the planet. Other members of this mineral group consist of labradorite (moonstone's sister stone), rainbow moonstone, sunstone, and amazonite. Moonstone and labradorite both have the cloudy irradescent glow that isn't found in any other stone in the world. Is Rainbow Moonstone a Real Moonstone? Rainbow moonstone technically isn't even moonstone at all but a variation of labradorite. It's translucent beauty is hard to deny and makes an amazing statement piece! Rainbow moonstone pieces are so beautiful and...