A 28-carat diamond just became the most expensive jewel ever auctioned online after selling for over $2.1 million

• On Tuesday, Christie's auctioned off the most expensive jewel ever sold on an online auction.
• The 28.86-carat diamond sold for over $2 million.
• One of the rarest in the world, the Type 11a diamond was formed with pure carbon.

Christie's just broke a world record.

The auction house sold a 28.86-carat diamond for $2,115,000 in an online auction — the most expensive diamond to ever be auctioned online, Annabelle Spranklen reported for Tatler. The diamond sold for above its upper estimate of $2 million, according to Forbes.

The sale happened on Tuesday, the final day of Christie's Jewels Online sale. Spranklen writes that the diamond, a rare Type 11A, is classified as D-color, meaning it's one of the clearest diamonds in the world.

It also one of the rarest in the world, due to the fact that it's emerald-cut and formed with pure carbon. According to the Telegraph, the diamond is completely colorless with no impurities — under 2% of the world's diamonds can be classified at Type 11A.

The record-setting sale also bodes well for the auction house's future online auctions.

"The spectacular 28.86-carat D-color diamond received immediate attention upon its announcement," Christie's Head of Jewellery Rahul Kadakia said in a statement. "The stone possesses a transparency and purity which can only be found in the world's finest diamonds. The sale of this exceptional stone established the record for a jewel sold in an online-only auction, demonstrating greater client confidence in Christie's digital ability and online sale platform."