Hi, I recently acquired some very unique stones and one is a head-scratcher for me. One fluoresces under both short- and long-wave UV to a degree that I have never seen before; it makes the brightest florescent rubies I have look dim by comparison. I acquired four similar stones of the same size/appearance (except color). all of which measure the same (Mohs: >7, SG: >3, RI: 1.6 or so), and although one other shows very light fluorescence, this one glows way brighter than the visible brightness of the UV light source, it’s kinda nuts.
The pics aren’t great, but hopefully helpful. There are no real inclusions, but they are just slightly translucent around the edges with what I woke call a cotton-line internal appearance (somewhat off white cottony “texture” inside the stones (sorry, that’s the best description I could come up with).
In the UV pics below, the first is sw, the second lw UV. Not adjacent ruby (circled) is so overwhelmed by brightness of this stone it’s florescence is hardly visible.
Any idea what this may be? It doesn’t look like kunzite, one possibility I considered, but I’m stumped.
That is possible, but it seems quite unlikely given the source (I know precisely where they were found, and they were definitely not synthesized at any point in the past couple hundred years, at least). It’s just the one that fluoresces like this, the others (of the same shape and, at least in terms of measurements) type, do not (well, the blue does to a very small degree).
I realized I was posted the wrong RI and SG in the original post (which I’ll try and edit note). The RI is 1.65 for all stones, and the SG is roughly 3-3.2. I looked at them carefully in the sunlight and if it’s a die, it’s somehow integrate into the minerals, there is no inclusion or layers that are discreetly florescent, it’s every visible particle of the stone. I also retested hardness and I believe it’s greater than 7.5, for what it’s worth.
Putting aside the florescent property of that specific stone, do you have any idea what kind of stones these might be?
If anyone is interested, I’m pretty sure I identified these stones as “Afganite”. There are a few for sale on etsy, and they seem to match mine very closely (both the strongly fluorescent one and the others). I had never heard of this stone, and apparently it’s pretty rare; found in a lapis mine originally in Afghanistan. I guess most are blue, but there are a few different colors, as I understand it. There’s not a lot of info out there but I feel lucky to have gotten them.
If anyone knows more about these, please let me know.
Afghanite has a hardness between 5.5 - 6. Its RI is fairly constrained between 1.52-1.53 with a slight birefringence.
I just recently received a 5.6ct cab (12 x 11 x 5mm) “Afghanite”. I’m a bit skeptical because it looks very much like Lapis. Loupe exam shows a good portion of non-opaque material near surface with inclusions of undefined blue mineral.
My attempt to measure RI has been challenging. I will keep working on that. Problem is the target material is only in the dome portion of the cab.
An accurate SG may not be sufficient because of the large portion of matrix, but I will be doing that next.
After LW UV, the semi-transparent material glows orange. I observed a stronger orange near the transition planes between the matrix and transparent material.
I would be curious to know about possible dye treatments and if it would be more detectable near the matrix transitions. Jacqueline (@JCBellGG) had mentioned that earlier in this conversation.
Thanks, Troy, all very good info, I appreciate you sharing.
I may be wrong on my guess for my stones, as they look nothing like yours (not remotely close) and I have colors that are not blue. I will try to measure RI and SG again today and share anything new/worth sharing. I know with certainty mine were not treated, at least not in modern times (although I’m quite sure than gemstone treatments were widespread even in ancient times). I know that because I got them at the sourced (that is, where they have been for at least 1000 years), and I was physically present at that source and bought them wet from the hands of a diver who found them. So that much I know. I also know the specific region wheee I got them was a very wealthy maritime crossroads between east and west for many millennia, and i’ve gotten many items from as far away as the Yellow River region of China and the highlands of SE Asia, to Afghanistan and even NE Africa (and,
am convinced, the Americas) from the same spot, so on one hand, I know they are not modern synthetics, but on the other hand, they could literally be from anywhere.
I’ve finally broken down and decided to have a bunch of stuff tested with as much specificity as I can get. Again, if I learn anything interesting (IMHO), I’ll share, I’d love your feedback.
