Talk:Synthetic diamond
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Diamond simulants
Isn't any page about artificial diamonds incomplete without mentioning cubic zirconia's as diamond substitutes?
- Cubic Zirconia is not diamond, so this would probably best fit under "Related article" or "See also".
- Acegikmo1 18:08, 23 Jul 2004 (UTC)
History
What about James Ballantyne (Hannay), I think (although it would require some verification) that he claimed to have produced very small synthetic diamonds in the 1880s by heating carbon under pressure in a kiln, a claim which was widely disputed at the time. However his 'diamonds' were sent to the british museum of natural history where upon rediscovery some years later they where found not only to be real diamonds, but also of a type consistent with synthetic construction.
Yellow tint
The following sentence is contradictory:
"The yellow tint occurs when less than five out of each 100,000 carbon atoms in the diamond crystal lattice are replaced with nitrogen atoms. Technically it is a contaminant, but colored diamonds are more profitable because they can be made more quickly, cost less to manufacture, and are very popular".
The part that says "Technically it is a contaminant, but [...]" implies that there is too much contaminant. Which is wrong ! Because the synthetic process naturally leads to these low levels of contaminant (nitrogen atoms).
Or maybe the error is that "[...] when less than five out of [...]" should be replaced by "[...] when more than five out of [...]". In this case the sentence would be perfectly logical. -- R. Duxx
- I think it means that ANY number of non-carbon material is in the lattice that technically it is a contaminant, though in this case a desirable one. Dalf | Talk 09:29, 11 May 2005 (UTC)
- You don't get my point (or maybe I don't understand you :P). No, it is not desirable to have contaminant (because if we had too much contaminant, there would be no yellow tint). -- R. Duxx
CVD Process
Another statement is contradictory:
"[it] uses the low-pressure technique of chemical vapor deposition (CVD) to produce [diamonds]. The diamond produced is a single crystal, as opposed to the polycrystalline patchworks formerly produced by CVD."
So basically it says "it uses CVD to produce diamonds which are not like the ones produced by CVD". What a pity, after having read this article about diamonds, I am now even more confused...
High Temperature, High Pressure (HTHP)
(A process) developed by Gemesis, makes diamonds that may contain impurities in about 100 hours, by mimicing the natural process.
Statements where reasonable people may disagree
- HTHP, developed by Gemesis
- HTHP stands for High Temperature High Pressure. This adjective is used in other contexts (such as color treatments), besides lab-grown diamonds.
- Many lab-grown gems (such as sapphires) are subjected to HTHP color treatments in addition to the process(es) used to grow the gem.
Chemical Vapor Deposition (CVD)
CVD, chemical vapor deposition, builds diamonds by precipitation from carbon plasma and builds up at half a millimeter a day, and has a theoretical limit of several inches.
Statements where reasonable people may disagree
- (CVD diamonds) are said to be flawless in clarity.
- Many industrial CVD diamonds are quite cheap. (About $1 per carat, for diamonds that are a few centimeters long and a fraction of a millimeter thick.) Unfortunately, many of these diamonds are golden-brown, like a well-done cake.
~ender 2004-09-04 MST 19:22
History
I'm somehow skeptical that only two minor companies should be listed as making synthetic industrial diamonds. I was under the impression that the technique existed quite before these companies (not for making diamonds suitables for jewelry, but for making diamonds for industrial uses, i.e. tools). David.Monniaux 05:02, 11 May 2005 (UTC)
- The two listed companies are attempting to sell synthetic diamonds as gems. There is a large industry (about 400 million carats produced annually, or 4 times natural production) supplying synthetic industrial diamonds. I will try to update the article with this information in the next few days. - Bryan is Bantman 06:04, May 11, 2005 (UTC)