Hello all, Here are a group of pink Spinel I have been examining. I'm mostly comfortable with my conclusions, but I'd love for you to have a look and let me know if your thoughts are any different. Regarding Spinel in general, it's the gemstone I'm am most interested in pursuing right now. The only concern I have is that flux/hydrothermal synthetics can be incredibly convincing.
One question I have for the experts: is an expert level of experience examining inclusions sufficient for you to separate natural from synthetic Spinel, or are capabilities like UV-VIS-NIR / FT-IR / RAMAN Microspectroscopy now considered basic required tools for a field gemologist, like a microscope or refractometer.
Here's what I have for some Spinel specimens. Stones are posted in same order as photo (1 - 6). RI: 1.71 SG: Not tested LWUV: Strong SWUV: Weak Birefringence: Not observed Pleochroism: Not observed Dichroism: Not observed Polariscope reaction: ADR (some inclusions exhibit DR, and some remain light throughout rotation which I suspect is due to microcrystalline structure) Purchase location: Afghanistan Stated origin: Badakhshan Province Price: Stone 1 - 2.34ct Rectangle Purplish Red $70/ct; Stones 2,3,5,6 Purplish pink 3.88cttw $100/ct; Stone 4 Light Pink 2.1ct Pear $300/ct
Regarding these specimens, I am confident that 2,3,5, and 6 are natural due to what looks to me like Euhedral and Anhedral crystals (perhaps amphibole and/or apatite).
For 1 and 4, I also think they are natural. I found what looks like negative crystal and fingerprints in 1. In 4 it looks to me like there are tiny anhedral and octahedral crystals, a "flying pyramid", and sulphur deposits.
I am a beginner at microscopy and photography, but I'm guessing that your experience plus my crappy pictures will garner a more accurate interpretation than my eyes looking down the tubes. I'm not sure if my photos are adequate, but assuming they look familiar to you, my question is whether this is sufficient for positive ID of natural origin or if something like raman would be necessary to achieve certainty.
Let me now if there are any questions or any other angles etc. you'd like to see. Enjoy!
Spinel #5 crystal inclusion (apatite?). Part of the crystal is out of focus, but it's a fully formed structure floating in the gem and each surface can be brought sharply in to focus. It's right in the face of the table, but it's a very beautiful inclusion.
I wonder if you could offset the location of the inclusion by marketing a microscopic picture with the gemstone?
I'm using a refurbished Leica StereoZoom 6 courtesy of Jeff Wildman's Porta Lab, combined with my Samsung Galaxy S6 camera
I was strongly considering investing in the Eickhorst trinocular, but after reading the ad nauseum discussions here regarding microscopes (anyone here miss those days from a few years ago?) I concluded that Jeff's kit was the best value for acquiring the essentials, especially given the environment I'm exposing it to. Jeff is a wonderful person so I couldn't be happier all around with the recommendation and with his execution.
My girlfriend was the first to appreciate the resemblance to a boot, then a good laugh turned to despair as she informed me she would be perpetually appreciating "her boot". Spinel happens to be her birthstone so it works out. Now I'm charged to find a collection of greyish accents for a ring.
Raj, thank you for the compliment. Out of such a small sampling I'm astounded by the variety of internal beauty discovered. It's a magical material and I can't wait to find more. I'm sure I'm not alone in saying I'd love to see some of your collection.
The stereozoom 6 is nice--the old discussions rag on it a bit because that one list has it as 'not recommended', and its construction is more plasticy than earlier SZ models (it's amazing how much lighter it is than a stereozoom 5!) but honestly I think that list is mostly about how happy they were to do maintenance work on them. The ones I've used have had very nice ergonomics and produced a good image.
You can always upgrade to trinocular later, either an SZ6photo/SZ7 with photo port as a drop-in replacement, or with an adapter you can use a standard 76mm head. The adapters are kind of scarce but sometimes you'll find a head with one, like this Wild M7: https://www.ebay.com/itm/Wild-Heerbrugg ... 3742860713
The porta lab is a very cool concept. I haven't used the Gemological Products one, but the GIA one is an exceptional piece of equipment (I am not sure what their precise relationship is).
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