Gold Crafters Exchange and Joden Jewelry are two retailers who buy used gemstones. Their gem-buying websites are GoldCraftersExchange.com and SellMyDiamonds.com, respectively. TiffanyBuyer.com is an online buyer of used gemstones.
Gold Crafters Exchange buys precious and semi-precious stones whether they are in a setting or loose. The stones they buy include diamonds, emeralds, amber, rubies, tiger eye and sapphire.
Joden Jewelry buys diamonds and colored stones that are over 1 carat. The stones must be natural and non heat treated. They do not buy rough or uncut stones.
As of 2015, TiffanyBuyer.com purchases precious stones including jade, opal, sapphire, emeralds, rubies and alexandrite.