Color enhanced diamond changes colors as a function of light


Nov 17, 2015
Hello All,

Thank you for reading my post. I recently purchased a GIA certified Fancy Light Brown diamond with a faint fluorescence. The clarity is VVS2 and distribution is even. I had the stone treated. I think it was irradiated. (I am very pleased with the results of the treatment) However, I have a question about the science behind the color changes.

This diamond is quite unique. It changes color as a function of the lighting. I have seen this stone bright pink, peach, purple and brown. It makes a difference if it is outside or inside under incandescent or LED lighting.

I have taken the stone into my lab and put it under a 285 UV light source, but no color change. The lamp has two settings, but I can’t recall the second setting. (I am an organic chemist and it’s our common UV lamp for checking TLC plates.)

Can someone help explain what is happening inside the stone to give off such a different color shade?

Thank you for your help and comments. My fiancé loves the stone, but as a scientist I am very curious.

Thank you for your time  img_3387.jpg
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Jun 29, 2008
Re: Color enhanced diamond changes colors as a function of l

Your stone is intriguing because it doesn't react like any diamond (irradiated or otherwise that I've ever seen). Diamonds with fluoresence can appear to be different colours (ie white at times yellow or blue at others) but even chameleon diamonds don't change like this. What your stone looks like is a colour change garnet rather than a diamond but you say you have a GIA report? Was the stone bought from a reputable dealer and does the GIA report these colour changes?

Even irradiated diamonds don't turn a stone into a colour changer (which is what you have).

Sooooooooooooo if this is a diamond then it's highly unusual. I would definitely advise to get this checked out because worst case scenario is that the diamond has been switched somewhere along the line and is either a synthetic vanadium laced stone or a sapphire/garnet colour changer. These could be checked out with a good jeweller by the stone's RI for a "yes/no this is a diamond".

I'm very interested in what you find out.
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