Maybe that’s not entirely true, but the fact is that Costco sold their most expensive diamond last week, and Christie’s New York Auction did not.

Source: Costco

Costco’s 6.77-carat, D-color, internally flawless stone, valued at $1.6 million, sold for a Costco steal of $1 million. On the other hand, the highly anticipated 10.09-carat cushion-cut, purple-pink diamond ring, expected to go for $12-15 Million, failed to sell at auction. Fewer than 10% of pink diamonds mined are larger than .2 carats, so this big beauty was poised to be a record breaking seller.

Source: Christie's

In a time where colored gemstones and diamonds are in vogue for engagement rings (Kate Middleton’s Blue Sapphire, Jessica Simpson’s Ruby and Carrie Underwood’s Yellow Diamond) how did this rare diamond miss the mark?

Though this surprise likely has little to do with Costco’s move in the diamond market, high-net-worth buyers are still being cautious about over paying and aren’t afraid to hold out for a better deal.