Malaya Garnet Turn Green Under UVB?

Gem Related Discussion
1

Hello all — I recently came across a beautiful stone marketed as Malaya garnet from Mahenge region. It display the typical color shift (orangy red to pink to light cinnamon) in variety of lighting environments. It contains fine rutile that’s slightly visible under strong direct light or under the loupe. When I put it under the 311nm UVB light, it turned green, which is very unusual. Anyone can offer any insights? I am attaching two videos for your reference.

  1. Turn green: https://www.youtube.com/watch?v=az19VSuhWLU

  2. Regular light: https://www.youtube.com/watch?v=aL1GJtZlh0o

Also, the stone is 7.5ct for $5,500. Is that a fair price for this material?

Thanks.

2

Hello there,

The best thing to do here would be to use other tests as fluorescence is not a diagnostic result. Do you have any other tools ?
Do you also have a 365 nm UV light? 311nm is not a usual longwave we use in gemology.

Otherwise, it would be great to bring it to an accredited gemologist to make sure you bought the right gemstone.

3

Thanks. The seller agree to submit it to the AGS to be certified. The seller is a seasoned gem stone dealer, and he has never seen something turn green like this one under the UV light. Honestly, seems to not be able to find any literature stung a red stone turn green under UV light either.

4

This is good news, Great !

I agree it should have appeared red or inert. Now I remember that some synthetic gems such as Nanosital are sold as Mahenge garnets, and they appear green under longwave UV lights.

But let’s wait for the results before taking it for granted. It’s a little weird that the gems dealer did not make any tests before selling it.