Tenacious D was certified diamond by the Recording Industry Association of America.
 The Gemological Institute of America (GIA) developed 11 clarity scales to decide the quality of a diamond for its sale value
 According to the Rio Tinto, in 2002 the diamonds produced and released to the market were valued at US$9 billion as rough diamonds, US$14 billion after being cut and polished, US$28 billion in wholesale diamond jewelry, and US$57 billion in retail sales

