The Rare Ruby

This is yet another expensive gemstone sold by Sotheby’s. This time it’s a rare ruby weighing over 25 carats. Like other gems on this list, this rare ruby is complemented by diamonds.

Interestingly, rubies of this size are very hard to find. This is reportedly due to the geographic conditions required for rubies to develop.

Although some might just call it red, this ruby is typically referred to as “pigeon blood red” by gem experts. The stone gets that coloring from “well-balanced” trace elements. These elements include chromium, a hard metal that actually appears steel-gray on its own.

The diamonds on either side of this ruby are marked by Cartier, a luxury jewelry maker.

Price: 28,250,000 CHF (about $30.5 million USD)

Year Sold: Believed to be around 2015

Number of Carats: 25.596

Interesting Fact: Described as “pigeon blood red”