Uncle John knows pretty much everything—and if he doesn’t, he heads his massive research library, or puts one of his many associates on the case. So go ahead: In the comments below, ask Uncle John anything. (And if we answer your question sometime, we’ll send you a free book!)

What exactly are those “chocolate diamonds” I’ve seen advertised?

Diamonds are rare, diamonds are expensive, diamonds are a girl’s best friend, a diamond should cost two months salary, and diamonds should follow the 3 “Cs” of cut, clarity, color, and carat weight. There are a lot of notions out there about diamonds, and almost all of them come to us through years of aggressive marketing by the diamond jewelry industry.
For decades, “chocolate diamonds” have been referred to in the mining industry as, simply enough, “brown diamonds.” Because they’re naturally brown and not clear and shimmery like the more palatable jewelry grade diamonds, they were used for industrial purposes (primarily in huge drill bits for ore mining operations). Why are they brown? Degradation over time and infestation by nickel deposits.
The leading producer of brown diamonds is Australia. However, the diamond industry has developed a process in which high heat and pressure are exerted on brown diamonds and it turns them near-colorless. At any rate, and even with the treatment, brown diamonds are less expensive than naturally clear diamonds. They’re also “cruelty-free”—they’re not mined under poor working conditions in Africa.
In 2000, jeweler Le Vian began buying up large quantities of brown diamonds…and kept them brown. They came up with a marketing term to make them more palatable, and they trademarked it: Chocolate Diamonds.