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The NBA player has apparently listed the ring for an Oct. 15 sale at Christie's auction house in New York City. Humphries is not named explicitly as the seller, but according to RumorFix, which first reported the news, the ring in question is identical to the one Kardashian wore during her brief engagement and marriage to the athlete.
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A rep for Christie's confirmed to the site that the bauble up for auction is a Lorraine Schwartz creation with a 16.21-carat center diamond and two 1.80-carat side diamonds -- the exact dimensions of Kardashian's ring. The auction house could not disclose the seller's name but said it was "a gentleman."
"It is 100 percent the same ring," a source close to the reality star and new mom, 32, tells Us Weekly. "Kim has been waiting for the day he would auction it. Everyone always asked what Kim did with the ring -- she silently gave it back over a year ago! And Kris waited until the divorce was final to sell it."
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The ring is expected to fetch between $300,000 and $500,000 at auction, RumorFix notes -- significantly less than the $2 million it was reported to be worth when Humphries popped the question in May 2011.
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"The ring is definitely not worth $2 million, not even half of that," the source tells Us, noting that Kardashian paid for the gem herself.
In any case, the Keeping Up With the Kardashians star now has something she values much more -- a daughter, North, with boyfriend Kanye West. She and the rapper welcomed their first child in June.
This article originally appeared on Usmagazine.com: Kris Humphries Auctioning Off Kim Kardashian's Giant Engagement Ring