Not true. The Russians are sitting on a lode of gem quality diamonds in a meteor crator where there are an estimated several trillion carats of high quality diamonds. Diamonds are also mined in India, Australia, Canada, Russia, Brazil, Venezuela, Guyana, and in the U.S. Russia is the largest producer of diamonds. . . and the de Beers cartel has no control over anything except part of the African market and that is waning.
Black diamonds, none of which were ever mined in normal diamond mines, which other than red diamonds were considered the rarest fancy color diamonds were traditionally found strewn on the ground in central Africa and South America and were usually the size of a pea or smaller. Most were the size of grains of sand and are used in jewelry as pavé settings. Black diamonds are, as a rule, very slightly lighter but very slightly harder than other color diamonds.
Up to 15 years ago only three black diamonds were much larger than that size. The largest two were the greater and lesser Black Orlovs, both were in the Crown Jewels of the Russian Tzar. The Greater Black Orlov is about the size and shape of half a chicken egg at 667 carats and is striated with brown and white inclusions and is mounted in the Tzar’s Scepter. It’s a crappy diamond. The lesser Black Orlov is a far better quality diamond weighing in at 67.5 carats and is mounted in a necklace made of a 128 white diamond brooch suspended from a 124 diamond 18k gold chain.
The Lesser Black Orlov
The next largest was a 32 carat pendant.
Given the distribution of black diamonds and their chemical impurities, it is thought that all black diamonds come from a single source; a huge one kilometer in diameter black diamond asteroid that was born in the center of a supernova which struck the earth about two billion years ago and may have been the initiating event that broke up the super-continent on Pangea, striking right where the land masses of Proto-Africa and protests-South-America were joined, and burying itself in the earth, after strewing small fragments of itself over thousands of square miles.
About fifteen years ago, someone in Africa dug into a lode of black diamonds, perhaps even the main body of that asteroid, or a huge piece of it, and much larger cut black diamonds started appearing on the market from a mysterious source. These black diamonds were being cut in Israel and India and were not under the control of the de Beers Diamond Cartel so were not price nor supplied controlled. . . and much larger carat stones became available.
I designed and had made a solitaire man’s ring with a 15 1/2 carat black diamond in rose gold which I wear daily.
Swordmaker’s and Kathy’s black diamond rings
I did the same for a six carat black diamond with 28 champagne diamonds in yellow gold for my girlfriend. I own a 121 carat black diamond I’m trying to think of a good use for. . . I’m thinking gearshift knob, cane topper, or club. . . It’s a 1¼ " in diameter round cut.
Swordmaker’s 121 carat black diamond
I had an opportunity to buy a 255 carat black diamond but it was only about 3/32 of an inch larger in diameter than the 121 carat I already owned and was lesser in quality, I passed. It was a great demonstration of the square-cube law. . .
About five years ago, the supply of black diamonds started to dwindle. It seems that Communist rebels overran the African location where the source was and the mine was either shut down our sealed by explosives. The prices started climbing, going up by ten or more times what they had been when they first appeared for sale. I now seldom see large black diamonds offered.
Getting back to your original point. Diamond is not a scarce gem. If it were not a controlled market, gem quality diamonds would sell for around $15 per carat.