about colored stones

[mara54]

Can anyone please tell me about colored diamonds? I have heard they are a very big expense yet what does it mean by Fancy blue enhanced or fancy pink enhanced? Color treated? I love the color of the stones so any information would be helpful. Tky!!

 

[valeria101]

Date: 2/28/2006 7:17:44 PM
Author:mara54


I have heard they are a very big expense yet what does it mean by Fancy blue enhanced or fancy pink enhanced? Color treated?

Yes... color treated. The blue are irradiated and heat treated, the pink... I honestly don't quite know: some light ones are HPHT, some darker pinks - probably something else.

Trying a quick shot at a hairy topic:

There are a couple of thread on the 'Colored Stones' forum about treated diamonds, but not too much.

By color, as far as I know...


Blue: synthetics (intense to dark color), and irradiated (bright greenish-blue, not similar to natural blue color, although very, very rare greenish blue naturals exist). The irradiated are relatively inexpensive - with prices comparable to the brown diamond material they were before treatment. Synthetics are priced a bit higher than colorless.

Pink: synthetics (intense and stronger), HPHT (light to intense). HPHT must be only part of the treatment and there should be different types - resulting in light pinks and more recently, vivid reddish colors through a version of the treatment. Both types are more expensive than near colorless diamonds, but nowhere as expensive as natural pink. There are relatively few pink HPHT larger than 1 carat, and to my amazement, I have seen them offered at very high prices (e.g. > 20k/ct for 2 cts 'Bellataire' fancy pink). Huh? No idea if these goods really do sell that high or that was merely a PR 'event'

Green... irradiated. Same story as the blue. The colors are not terribly naturalistic, down to deep forest-green and the like. Interestingly, gemological tests have some trouble telling natural greens from synthetics of similar quality. Tests are typically expensive and slow on high clarity green diamonds (sic

) under this assumption of ambiguity. However, I am not aware of such natural-looking fancy greens being produced via treatment to begin with. One explanation I have been offered is that the material needed to obtain the light green treated stones would be high grade - colorless or near colorless, high clarity stones that need no help to sell - unlike the brown and tinted ones that are object of color treatments.
On the other hand, irradiation also produces vivid greenish-yellows that do look like their rare natural counterparts.

Yellow, orange & all in between: synthetics (prices comparable to natural fancy light yellow) and irradiated (less expensive, priced as perhaps natural browns would) are available. All have shocking 'intense' or stronger colors - fairly realistic and possible untreated.... once in a blue moon.

There are some interesting reports about treated 'red' diamonds on www.GIA.edu and elsewhere on the net. Worth looking, IMO. Other websites: Chatham, Takara and the 'Colored Stone' forum right here

My 2c

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Whatever the appeal of a... $30k vivid pink of a third or a quarter carat, that surely is lost with a synthetic or treated diamond. At some point, the appeal of either is quite a mystery to me

case in point