While both the Holo and Reverse Holo versions can sell for north of $40, the Reverse Holo's highest sale reached as high as $44.52, while the most expensive Holo Rare only managed to hit $41.71.

6. Sapphire Price per CD: $243,702 Sapphire, next on the list of most expensive gemstones in the world is a variety of corundum, which is aluminum-oxide.