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 Post subject: Re: Prasiolite from sri kanka
PostPosted: Mon Mar 23, 2020 2:17 am 
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1bwana1 wrote:
Separation is possible, just not practical considering the values involved.


Funny. Natural top color clean amethyst costs me 5 - 10 x the price I would pay for the same color in lab-grown.

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 Post subject: Re: Prasiolite from sri kanka
PostPosted: Mon Mar 23, 2020 10:52 am 
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Yes, but in the scope of the price of gemstones the value of both are still very low.

The last time I bought a few kilos of top color, clean, large size Amethyst from Rwanda it cost me about $1.00 per gram so about $0.20 a carat. South American is about double that for the best quality even though the color is not as red/blue dichroic as the Rwanda Amethyst.

The synthetic is available in kilo lots for about $0.05 a gram so worth cutting and mixing into natural parcels.

Real and natural are both inexpensive and often mixed in the production parcels. So, it is not cost effective owning the equipment or spending the time to do the separation.

GIA agrees:

https://www.gia.edu/gia-faq-reports-for-amethyst


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 Post subject: Re: Prasiolite from sri kanka
PostPosted: Mon Mar 23, 2020 2:10 pm 
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Barbra Voltaire, FGG wrote:
I have never seen naturally occurring lemon quartz. Anyone?


According to my supplier the stone has not gone under any treatment .
I Would send it to GIA, but i think the certification would cost more than the stone itself :D Supposed the stone is unheated Does it have more value ?

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 Post subject: Re: Prasiolite from sri kanka
PostPosted: Mon Mar 23, 2020 3:07 pm 
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No difference in price.

I am not sure that any of the labs offer reports on whether an Amethyst has been heated or not. This is true of many stones where the heat required to do the treatment is low like it is in Amethyst. The treatment leaves no traces so cannot be determined.

Unless your supplier had the stone in his hands from mining to delivering to you, he also cannot guarantee that there is no heat treatment.

I follow the AGTA requirements for treatment disclosure. It is a bit tougher than U.S. law, but is reasonable and needed.

If you really want to start understanding treatments and disclosure you should read about it here. Your supplier clearly should not have made that representation.

https://agta.org/wp-content/uploads/201 ... Manual.pdf


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 Post subject: Re: Prasiolite from sri kanka
PostPosted: Mon Mar 23, 2020 3:27 pm 
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As with pinked topaz, I do not believe a test exists that will identify heating in amethyst.


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