Metallica's The Black Album received RIAA 2× Diamond certification in 2025.
The Recording Industry Association of America uses Diamond certification for shipments of ten million units in the United States. A 2× Diamond award therefore represents twenty million US copies shipped. The album reached that milestone after decades of sustained sales.
The certification also reflects the unusual durability of The Black Album in the American market. It became the first album of the Nielsen SoundScan era to pass 20 million US copies, according to the album's documented sales history.
This achievement is separate from worldwide sales figures and from chart longevity. The Black Album has sold more than 30 million copies worldwide, while its US certification is based on RIAA shipment thresholds. Keeping those measures distinct avoids confusing a certification level with a global sales total.