THESE ARE EXTREMELY RARE!! I purchased these from Tiffany & Co at Santana Row in San Jose, CA about ... I don't even know... maybe 20 years ago. I've barely worn them, so they are in excellent condition. The stones are Crystal Quartz. You can look them up by typing in "Tiffany 20 Carat Collection". The lack of color in the stone, combined with the silver color is just stunning. The backings are not originals, but are silver and fit these earring perfectly. They are slightly different from each other, but no one will notice.