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I agree. Synthetic diamonds are available and generally run about 25% less per carat than an equivalent quality natural stone. This pricing is high in view of t

I agree. Synthetic diamonds are available and generally run about 25% less per carat than an equivalent quality natural stone. This pricing is high in view of the relatively low production costs. Gemesis and other companies were successful in driving down the cost of capital equipment for making diamonds by the older high pressure, high temperature process. Chemical vapor deposition of high quality diamonds is well established and doesn't cost much at all. Market pricing for aesthetic applications of diamonds continues to be only loosely related to cost of production. I think this will continue until the Maker movement decides it would be cool to have diamond doorknobs, at which point the price will drop to something more closely related to the cost of arranging sp3 bonds between carbon atoms under metastable conditions - i.e., not much. edited for a typo

ericfranklin 12y ago
As a producer of synthetic diamonds (http://d.neadiamonds.com http://d.neadiamonds.com), I can say the production costs for jewelry-quality diamonds are not as low as people seem to think. It is one thing producing brown/yellow diamond powder/grit for cutting tools, but is orders of magnitude more difficult growing a large single-crystal diamond colorless and clean enough to set into jewelry. The capital equipment for HPHT and CVD are both still quite expensive. It is possible to find some used BARS presses for reasonable prices, but you will be hard-pressed to make a large colorless diamond with one of those machines, even if you know the right "recipe" to use. Gemesis has many of these BARS presses and they have only been able to produce orange yellows and to treat CVD material with them. CVD does grow more crystals per machine cycle, but also has much higher labor, power and support costs than the latest generation of HPHT machines. CVD diamonds also typically grow as a brownish or grayish color and have to be HPHT-treated (different process than HPHT-growing, but can be done in the same machines) at additional cost to whiten them, healing defects in the crystal lattice. The cost to grow a rough white diamond is generally comparable with the cost to mine one from the ground. From there, the cutting, grading, logistics and jewelry all cost essentially the same. Lab-grown diamonds are a raw good, more similar to steel, than they are an assembled good, like a TV or laptop. There will certainly be more improvements along the way, but diamond synthesis only occurs under certain conditions defined by nature. Changing the crystalline structure of carbon is a bit more involved than heating up some filament for a 3D printer.
- ridgeguy 12y ago
  Thanks for your informative comment. I know less about HPHT diamond synthesis, and may not understand the cost structure of that technology as well as I would like. I agree re the current high capital cost of CVD diamond synthesis equipment, but I'm pretty certain it need not remain so. For example, in microwave plasma assisted diamond CVD, significant slices of the cost pie are in the microwave power source and the deposition chamber. The former tends not to take advantage of 2.45 GHz consumer sources and is, I think, overpriced in $/Watt compared to what it could be with some additional electronic design work. The latter suffers because diamond microwave CVD chambers tend to be one-offs. Building them in hundreds or thousands would allow lower cost manufacturing technologies to be used. Power costs are an issue, but there are ways of extending the lifetime of atomic hydrogen, which is a key cost determinant of CVD diamond. Labor costs will be reducible to the extent that CVD processes can be automated, which I regard as largely a matter of getting reproducible processes in hand. When you have a predictable process, you can automate it. I concur it will be awhile before my Replicator 2 can spit out a diamond filament. But I think the current manufacturing cost of diamonds is far higher than what it might be. The missing link is somebody willing to fund the volume manufacturing process development.

ericfranklin 12y ago

As a producer of synthetic diamonds (http://d.neadiamonds.com http://d.neadiamonds.com), I can say the production costs for jewelry-quality diamonds are not as low as people seem to think. It is one thing producing brown/yellow diamond powder/grit for cutting tools, but is orders of magnitude more difficult growing a large single-crystal diamond colorless and clean enough to set into jewelry. The capital equipment for HPHT and CVD are both still quite expensive. It is possible to find some used BARS presses for reasonable prices, but you will be hard-pressed to make a large colorless diamond with one of those machines, even if you know the right "recipe" to use. Gemesis has many of these BARS presses and they have only been able to produce orange yellows and to treat CVD material with them. CVD does grow more crystals per machine cycle, but also has much higher labor, power and support costs than the latest generation of HPHT machines. CVD diamonds also typically grow as a brownish or grayish color and have to be HPHT-treated (different process than HPHT-growing, but can be done in the same machines) at additional cost to whiten them, healing defects in the crystal lattice. The cost to grow a rough white diamond is generally comparable with the cost to mine one from the ground. From there, the cutting, grading, logistics and jewelry all cost essentially the same. Lab-grown diamonds are a raw good, more similar to steel, than they are an assembled good, like a TV or laptop. There will certainly be more improvements along the way, but diamond synthesis only occurs under certain conditions defined by nature. Changing the crystalline structure of carbon is a bit more involved than heating up some filament for a 3D printer.

ridgeguy 12y ago
Thanks for your informative comment. I know less about HPHT diamond synthesis, and may not understand the cost structure of that technology as well as I would like. I agree re the current high capital cost of CVD diamond synthesis equipment, but I'm pretty certain it need not remain so. For example, in microwave plasma assisted diamond CVD, significant slices of the cost pie are in the microwave power source and the deposition chamber. The former tends not to take advantage of 2.45 GHz consumer sources and is, I think, overpriced in $/Watt compared to what it could be with some additional electronic design work. The latter suffers because diamond microwave CVD chambers tend to be one-offs. Building them in hundreds or thousands would allow lower cost manufacturing technologies to be used. Power costs are an issue, but there are ways of extending the lifetime of atomic hydrogen, which is a key cost determinant of CVD diamond. Labor costs will be reducible to the extent that CVD processes can be automated, which I regard as largely a matter of getting reproducible processes in hand. When you have a predictable process, you can automate it. I concur it will be awhile before my Replicator 2 can spit out a diamond filament. But I think the current manufacturing cost of diamonds is far higher than what it might be. The missing link is somebody willing to fund the volume manufacturing process development.