Origin and Properties of Diamonds
When I was a small boy, a lazy one at that, I would sit on our coal pile out in the shed and slowly toss lumps of coal into the coal bucket. I knew that diamonds mostly came from deep in the earth in Africa and that they were formed by heat and pressure.
I decided that if I could form a cylinder with a plunger and put it in the ground and placed a metal pole extending high above it, I could form diamonds if lightning hit that pole and send a powerful stream of electricity down the pole, below the ground, and to the piston in my cylinder, and if I had crushed coal in the cylinder, the piston would force it down on the coal with great force and temperature and diamonds would be formed. I knew that coal was carbon and so were diamonds.
Over the years synthetic diamonds were developed. Tracy Hall produced industrial type diamonds at General Electric and did much research on the formation of diamonds at BYU. I have been to the laboratory at BYU and I have seen the presses that he designed to provide adequate pressure to form diamonds.
Industrial diamonds are used in grinding and cutting applications and they are not of gem quality.
Gem quality diamonds still come from mining operations, mostly in Africa although there are diamonds in other parts of the world. Their production and distribution is managed by a cartel just like petroleum. The cartel is well-known for its dislike of competition and I'm sure that if gem quality diamonds can be produced artificially, they own all the patents. (That was a joke.)
When I was in industry, my company owned all the major diamond jewelry manufacturing companies. I visited a couple of these companies as part of my job. We used gold in our fine china and crystal operations and the control of gold inventory and scrap was a major function. One company that I visited used lie detectors to keep an eye on their employees. If you think it is hard to board an airplane these days, you should see the precautions used to get into or out of a diamond, gold, platinum, etc., jewelry manufacturer. Of course the mine and processing facilities in Africa have controlled access and exit.
The most important properties of diamonds for jewelry are the hardness, the hardest of all natural minerals, the luster (and sparkle), the color and purity.
When you see a jeweler looking at a diamond with a hand (magnifying) lens, he is looking for not only the cut of the diamond but for imperfections. Diamonds don't have to be perfect to be beautiful in jewelry but some people feel that a diamond must be free of all flaws.
When I was in college, my friend bought his girl an engagement ring. Both of them worked with me in a research laboratory where we developed hard materials for the atomic energy commission and the abrasive industry.
The young women was thrilled with her ring until one of the mineralogy students thought it would be a good idea to take a look at it under the microscope in the mineralogy department. Well, the diamond did have a flaw or two. The young man took the ring back to the jeweler and exchanged it for a much smaller diamond, but one of total purity. When he gave this much smaller stone to his fiancé, she was heart broken. She called it, "The little token of his affection." He was too stubborn to return it and give his girlfriend the original ring which is the one she wanted. I hope the marriage worked out better than the ring situation.
When we lived in Arizona, I had a good friend who owned a jewelry store where he created his own jewelry. He traveled to Belgium every year to buy diamonds. He would be in Antwerp for a week looking at thousands of stones, selecting those that would fit into his jewelry manufacturing plans. He would come home with a small bag full of diamonds.
Diamonds are traded in New York City on the street. Diamond merchants walked around with diamonds in their pockets, trading and selling with those interested. They are not selling to the public but I assume if you walked up to one of these gentlemen with a hand full of cash he would sell you a stone. Then you could take it to a jeweler and have a ring, or what have you, made.
Buhl, Idaho