Tenebrescent diamond
30th Sep 2016 22:50 UTCAlexander Ringel
I found out fast, that the diamond has a strong and zoned fluorescence and a lasting phosphorescence. The phosphorescense can be stopped very fast when the diamond is placed in visible light. That brought my hackmanite in my memory. It has also a phosphorescence, which can be stopped with normal light and is known for it's tenebrescence. Now i wondered, if it could be possible, that the diamond shows also a tenebrescence. I guessed, that it would not last long and would probably be too weak to be noticed with normal eyes without the possibilty to compare. So i had an idea. I placed my camera with flash infront of it and made a photo in complete darkness from the diamond. Then i irridated it with UV and took imediately after shutting of the source another photo. A difference was clearly visible. The irridated diamond is a bit darker and the color tone shifted a bit. To exclude any mistakes i repeated it 2 times with the same result. The last time i took my 405 laser for irridation. It made the best result. The color change is weak, but visible.
These are the two pictures of the diamond before and after 405 nm laser irridation.
Here a composite photo of all 3 runs. The respective left side is before and right side is after irridation.
I guess this effect of short term tenebrescence is NOT very rare in phosphorescent minerals. Probably others should make similar tests with their phosphorescent mineral specimens of any kind. Would be nice to see more positive results.
Thanks for this information and linked papers. When i understand it correctly, my diamond is (almost) not a real chameleon diamond. It could be maybe with a bit of optimism defined as some kind of very weak reverse chameleon, which changes its color for a brief time when exposed to UV. Heating would not get any result, because its already yellow (and brown). But i would not risk it anyways. The fluorescence behavior of my specimen deviates from both chameleon groups (normal and reverse). Only the phosphorescence matches with the phosphorescence of the reverse group. I guess this kind of weak short term color change after UV is much more common than the real chameleons and just unmentioned or unnoticed.
After buying some new batteries for my microscope fitting camera i was able to make some pictures to show its normal unchanged colors a bit larger and in better quality. These pictures will not change anything, but they do definitly look better than the pictures above.
Phosphorescence color is more orange than on photo.
After buying some new batteries for my microscope fitting camera i was able to make some pictures to show its normal unchanged colors a bit larger and in better quality. These pictures will not change anything, but they do definitly look better than the pictures above.
Phosphorescence color is more orange than on photo.
