A “diamond” certification from the Recording Industry Association of America (RIAA) signifies that a song or album has sold at least 10 million copies. As of my knowledge cutoff in September 2021, there were only five rappers who had achieved diamond certification:
Eminem: The rapper has two diamond-certified albums, “The Marshall Mathers LP” and “The Eminem Show.”
Tupac Shakur: Tupac has two diamond-certified albums, “Greatest Hits” and “All Eyez on Me.”
Notorious B.I.G.: The rapper’s album “Life After Death” has been certified diamond.
OutKast: The hip-hop duo’s album “Speakerboxxx/The Love Below” has been certified diamond.
MC Hammer: The rapper’s album “Please Hammer, Don’t Hurt ‘Em” has been certified diamond.
It’s worth noting that these certifications are constantly changing as artists continue to sell records, so there may be additional rappers who have hit diamond since my knowledge cutoff.