Adele is about to join the elite club of diamond sellers.

No, that has nothing to do with expensive stones or jewelry. Rather, 21, her 2011 album, has sold in excess of 10 million copies in the United States, per Billboard, thus entitling it to "diamond" certification (that honor comes by way of the Recording Industry Association of America and is expected within the coming weeks).

Since Nielsen SoundScan started tracking sales data in 1991, only 21 albums have achieved the feat and crossed the coveted threshold, among them Alanis Morissette’s Jagged Little Pill, 'NSync's No Strings Attached, The Bodyguard soundtrack and Santana's Supernatural. Next in line to hit 10 million is likely -- and appropriately -- Pearl Jam's Ten, which has sold 9.98 million so far.

21 is one of only eight albums to hit the 10 million mark within two years of release (104 weeks), according to Billboard.

Adele’s second album spent more than 80 weeks in the top 10 of the Billboard 200 album chart, a tally that trails only Bruce Springsteen’s Born in the U.S.A. and The Sound of Music. Even as recently as July, 21 was declared the best-selling album of 2012 having moved over 3.6 million units this year alone.

No word yet on when Adele will start on a new album. The singer gave birth to her first child, a son, in October. Earlier that month, she released the song “Skyfall” from the James Bond film of the same name.