10 Most Rare and Valuable Gemstones

9. Moussaieff Red Diamond – est $20 million

The Moussaieff Red Diamond, once known as the Red Shield Diamond, is a small but rare 5.11 carat stone with a triangular brilliant cut. It’s colour was rated as Fancy Red by the Gemological Institute of America and it’s the largest red diamond currently known in the world. Discovered in the 1990s by a Brazilian farmer the stone originally weighed in at 13.9 carats. It was bought and cut by William Goldberg Diamond Corp, before being sold to Moussaieff Jewellers sometime in 2001 or 2002.

8. Flawless 100-carat Diamond – est $22 million

A recent entry to the gemstone scene this flawless 100 carat diamond sold in April of 2015 for $22 million at a New York auction. Currently unnamed, the stone is a classic emerald-cut D coloured diamond, and was bought by an anonymous bidder over the phone. Mined in Southern Africa, this walnut sized stone originally weighed in at 200 carats before more than a year was spent cutting and polishing it.