The 16.21-carat Lorraine Schwartz rectangular-cut diamond engagement ring that Kim Kardashian was given by second husband Kris Humphries sold at an auction on Tuesday.

The ring, which Humphries bought for around $2 million, was sold at Christie's auction house in New York City to an anonymous bidder for the low price of $620,000, but after auction fees a grand total of $749,000 was spent on the ring.

The winning bid came via a phone bidder; and a portion of the proceeds from the sale will go to charity.

Kardashian and Humphries were married for a whopping 72 days, after which they spent 19 months settling their divorce.

"It bounced between two phone bidders and two bidders in the back of the room," a Christie's spokesperson told E! News. "Good participation all around. It was the last item in the morning session."

Christie's wouldn't comment on who the seller of the ring was, but Humphries' rep told E! that the NBA player was the one behind the sale and that he was "very pleased with the final result".

Humphries is still in the process of deciding which charity will get the money from the sale.

The ring was expected to fetch between $300,000 and $500,000.