Here it is ... the first photo of the 4.09 carat blue diamond Drew Brees bought for $8.1 MILLION.
It's pretty incredible ... but the QB says he overpaid by roughly $6 MILLION!
TMZ Sports broke the story ... Brees purchased the stone as an investment from Vahid Moradi of CJ Charles jewelers in San Diego back in 2015 -- but says he was completely duped.
For his part, Moradi and his attorney Eric M. George deny all wrongdoing and say Brees has no one to blame but himself.
Brees claims he trusted Moradi to get him the best prices on rare stones in the hopes of selling them for a profit at a later date.
Brees says in 2018 he had the stone appraised by an independent specialist who told him the diamond was only worth $2 million when he bought it ... and it has since increased in value to $3.75 mil.
There's more ... Brees is also furious over pink diamond earrings he bought in 2015 for $975k -- claiming Moradi used pink paint behind the diamond setting to make the stone appear more "pink" than its true color.
Brees says the pink stones are only worth $176k.
In total, Brees says he spent $15 mil with Moradi over the years -- but his stones are only worth roughly $6 mil ... a $9 million loss.
For his part, Moradi says he did nothing wrong -- and claims Brees has no one to blame but himself.