Pink diamonds are already rare; only one in 10,000 diamonds is colored pink, according to Lucapa's CEP Stephen Wetherell. So factor in that this one is 170 carats, and you have one of the rarest gems on earth. The Lucapa Diamond Company discovered the pink tone, now named the Lulo Rose, at the Lulo alluvial mine in Angola, Africa. At its weight, the 170-carat diamond is the largest pink diamond found in the last 300 years. The Lulo Rose will be auctioned by Sodiam E.P, the Angolan State Diamond Marketing Company.