Johnny will call Jim to tell him about the diamond deal in Broker and he might need some help. Jim sends the Broker chapter to help him. Johnny then meets up with a group of the Broker chapter of The Lost MC, and proceeds to crash the diamond deal.
After a brief struggle in which Luis notices the bikers and alerts the others, Johnny and a few members proceed to follow a Stretch carrying the diamonds, and instructs another group of Lost members to follow Tony and Luis.
In order to complete the mission the player must:
- Meet the other Lost gang members
- Lead your brothers to the docks
- Take out Tony's boy
- Pick up the diamonds
- Take out Tony's Bodyguards
- Stash the diamonds in the two trash bags
- Evan Moss
- Evan's Bodyguards
The chase to get the diamonds consists of a Stretch and an Oracle, in which goes from Broker to Algonquin. When the limo stops, one of the passengers will try to escape. He is Gay Tony's boyfriend Evan Moss, who is carrying the diamonds. Johnny kills Evan and picks up the diamonds.
After gaining the diamonds, Ray instructs Johnny to place half of the diamonds in two different trash bags to be "picked up by my boys". Johnny places half of the ice on Hematite Street and the other half on Emerald Street. Occasionally, during the stash, another Oracle appears which are two of Gay Tony's bodyguards, after they are killed the player must store the last of the diamonds.
There is no reward for beating the mission, but if Roman's Holiday is completed, Ray will call the player to begin the next mission, Collector's Item.
Liberty Tree Newspaper
"Evan Moss, 24, was found murdered in Broker. When, at the age of sixteen, he won the Teen Iron Weightlifting Competition in Arizona, no one could have predicted this violent end. Tragically, his life took a turn for the worse. After positive drug tests, the loss of his weight supplement sponsorship deal, and alleged involvement in a male escort business he hit rock bottom."
"Moss had recently gained public attention as a star of the Liberty City nightclub scene. He was often sited with minor celebrities too drunk to know better at Algonquin hotspot Maisonette 9. It was even rumored that Moss had hooked the biggest whale in the Liberty City Scene - nightclub baron Tony Prince. Mr. Prince would not comment on his friend's untimely death. The LCPD are looking for a group of men wearing tight black leather in connection to the slaying."
Weazel News Newspaper
"Just when the homosexual community had gained a smatter of respectability by parodying themselves in reality TV shows and sitcoms, they go and ruin it for themselves. The death of Evan Moss, amateur body builder, drug addict and cum receptacle for "Gay" Tony Prince, got himself killed in the most brutal of fashions. This just goes to show that a deviant lifestyle will lead to an unfashionably early arrival at the sodomites' party in Hell. Deputy Mayor, Bryce Dawkins, weighed in on the issue "If America is to remain the moral Christian country I know it is, we need to take the vote away from these people. They can concentrate on picking out wallpaper and leave the choosing of our President to real men.""
- Evan Moss - Killed by Johnny to steal the diamonds.
- Evan's Bodyguards - Killed by Johnny to steal the diamonds.
- The mission reappears in The Ballad of Gay Tony, from the perspective of Luis and Tony; they must escape from The Lost members chasing them.
- The brothers can be seen facing the other direction and riding that way after the deal gets sabotaged.
- This mission is also connected to GTA IV mission Taking in the Trash, where Niko has to collect the diamonds left by Johnny from the trash cans with Luca and his partners.
- If the player calls Terry Thorpe and Clay Simons for backup before reaching the deal, they'll arrive with two additional Lost members and help the player to deal with Evan and his men, becoming a large group of twelve bikers with eight bikes. However, after the mission is completed, only two minor members remain alive, while the rest are deceased.
- In this mission, Luis, Tony, and Evan all flee in Stretch limos, but in Frosting on the Cake, they flee in Stretch Es. As well as this, the APC that appears halfway into Frosting on the Cake never appears in Diamonds in the Rough. Another difference is that Luis and Tony have less detailed faces in this mission; as opposed to Frosting on the Cake. These differences are obviously due to the fact that neither of these vehicles were integrated into the series at this point.
- In the pre-mission cutscene, Ray tells Johnny that he "knows about some diamonds" that are being bought "by wiseguys, from wiseguys, for wiseguys" (pointing to himself). Judging by this dialogue it can be assumed that Rocco Pelosi planned to have Tony and Luis buy the diamonds from The Cook so that he could sell them to Ray at a profit, Ray however plans to rip him off instead and take the diamonds for himself in order to sell them to Mori and Isaac at a later time.
- If Evan is killed in the water, the diamonds will get lost and the mission will fail.
- In the cutscene at the beginning, Ray refers to Tony as "Gay Tony", but when he calls for back-up and they arrive, Johnny refers to Tony as "Tony Prince", suggesting he might have already known his last name.
- If the player brings Terry and Clay along as backup, it's possible for one of them to kill Evan Moss instead of Johnny.
- This is Tony's only appearance in The Lost and Damned, similar to his singular appearance in Diamonds Are a Girl's Best Friend from GTA IV.
- There is a minor difference in the Cook's dialogue. In this mission, he says "Hey guys, how ya doin'? Err. So umm…", while in Frosting on the Cake, he says "Yeah…yeah alright. This is them"
- The title of this mission is a reference to the expression "diamonds in the rough" which is someone who has talents but lacks ambition or attention.