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 Post subject: Re: Gemesis to Mass-Produce Lab-Grown Colorless D
PostPosted: Thu May 05, 2011 10:47 am 
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Interesting article, but it is kind of confused. First it talkes about Gemesis and colored diamonds and HPHT which is what I have read about. Then it brings in the GIA and talks about colorless diamonds and CVD which I did not think the Gemesis did and certainly does not have the same tell tale characteristics as HPHT. I also like how the GIA reaffirms that it can tell the "cultured" diamonds from natural, but gives no cost for doing it.


Bruce


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 Post subject: Re: Gemesis to Mass-Produce Lab-Grown Colorless D
PostPosted: Thu May 05, 2011 11:15 am 
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bruce_tourm wrote:
Then it brings in the GIA and talks about colorless diamonds and CVD which I did not think the Gemesis did and certainly does not have the same tell tale characteristics as HPHT.


Peraphs Gemesis started to work on CVD, hence the difficulty to obtain +1 carat stones, which is not an issue with the HPHT process.
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 Post subject: Re: Gemesis to Mass-Produce Lab-Grown Colorless D
PostPosted: Thu May 05, 2011 1:44 pm 
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That's my understanding also, that Gemesis started - at least in intent, or in an experimental way, with chemical vapor deposition, with the primary goal of making diamond substrates for semi conductor use. This proving more difficult than anticipated, they then switched to a more proven technology. But that is from memory, which is vague, and may be wrong.

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Hans Durstling
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 Post subject: Re: Gemesis to Mass-Produce Lab-Grown Colorless D
PostPosted: Mon Oct 21, 2013 9:18 am 
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roshanravan wrote:
would happen if someday Synthetic Diamond enter the game specially in melee.
there are some trace to test & distinguish Synthetic Diamonds like:

-Spectroscopic tests such as infrared and UV.
-Cathode luminescence shows cross-like growth sectors in HPHT synthetics.
-Strain patterns are visible under polarized light.
-HPHT phosphorescence (after glow) once ultraviolet lamps are turned off.
-Fluorescence patterns differ to patterns in natural diamonds. Yellow-green -fluorescence in a yellow stone indicates that it is a HPHT synthetic; whereas red -fluorescence in a brown or colorless stone highlights that it is a CVD synthetic.
-Magnetic tests find that synthetics can be moved by a powerful magnet whereas diamonds cannot.

but considering the cost of examining does it worth it to test melee? how much time consuming that would be? and also what about ready jewelries with melee on them which make it harder even impossible to test? these are the question how synthetic might effect the market,

i have been read that DeBeers has control over producing synthetic and entering them into the market. also the cost of making Synthetic does not worth to do such thing.

again what would happen if number of companies able to do synthetic raise and they find cheaper ways? and how long DeBeers can control it? or maybe if the synthetic process gets cheap the DTC would decrease diamond prices to compete synthetics. but we cant be sure of any thing just possibilities & predictions.


Looks like our nightmare is becoming true.... :|

Quote:
RAPAPORT... TRADE ALERT: Buyers Beware. Persistent reports that large amounts of synthetic lab grown diamonds are being mixed with natural diamonds in parcels of melee and pointers. Know your supplier and insist phrase “natural, untreated diamonds” be included on all invoices.

Source: http://www.diamonds.net/news/NewsItem.a ... leID=44905

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