need help to gem experts of this forum

[LD]

Tariq from your photos on Flickr it looks like the stone doesn't react to UV light. Is that what you're seeing? What it looks like from the pictures is that it's just reflecting the light of the UV pen rather than fluorescing.

 

[iLander]

It could be quartz too. I don't think diamonds show that much facet abrasion.

Yes, good point.

Also, I have seen quartz with rainbow-type inclusions. Almost like an oil slick suspended in space, and they disappear when the stone is turned. I think the rainbows seem to be in the same place through all the photos, and it's not really a refraction. More like a suspension.

Now I am leaning toward quartz.

But then again, I'm easily swayed.

 

[Tariq wali]

thank you LD your raising point may be positive , i am not an expert will you pls guaid me how to check in UV light , and distance of UV and surrounding lighting environment , dim , dark , or moderate ? i will check again and will post another picture .

 

[LD]

Tariq if your stone has fluor then it will show even in a moderately lit room with the UV light a few inches away. You'll see the difference immediately. You won't struggle to see fluorescence. Even weak fluor is easy to see. Here's a photo of some of my stones that have fluor. These were all taken on different days with different lighting conditions but the fluor is obvious - that's what made me think that your stone was inert.

Edit: I've just realised that the background in the photos is the same in all cases (it's a beech wood table) but you can see how different it looks - that's just due to the time of day, the lighting that was/wasn't on the in the room etc. I haven't changed the lighting on purpose to get a particular look as these were taken over the course of a few years.

 

[Tariq wali]

LD you are right , my camera unable to capture fluorescent of stone ,rather camera capturing the blue effects of light .

i did a practical with my blue spinel , while its fluorescent red in uv light but canmera unable to capture its original fluorescent which is some type of purplish red , purple mixing a little bit but red is more countable clour, if u can feel the picture of uv light you can feel some slight red behind the blue flur of uv light , thank you for your point , i am mostly favourable of my yellow stone as a sapphire , i will go it for lab test .thanks you again

 

[Tariq wali]

one more

 

[LD]

Tariq

I will continue to research yellow sapphires and fluor but so far this is what I've found:-

"Natural yellow sapphires fluoresce yellow, synthetic yellow ones are inert. Natural colourless fluoresce orange, synthetic colourless are inert. Synthetic orange sapphire fluoresces red (from chromium).

Some synthetic corundum manufacturers (Ramaura) have in the past doped their products to allow identification using fluorescence as an indicator. Some of the new hydrothermal and flux-melt products however act very much like natural stones under all stimulation. It is necessary to review the literature to find references to new developments"

Charles Lewton Brain (1994)

Everything I'm reading suggests that synthetic corundum is inert. Yellow sapphires can fluoresce but I don't know if they can be inert as well. I will continue reading!

 

[LD]

I've just found this - can you run any tests because here's a few ways to separate yellow sapphire from others:-

Simulants (with separation tests):

Yellow Sapphire: Chrysoberyl (optic figure, spectrum, inclusions), Citrine (optic figure, R.I., S.G., inclusions), Topaz (optic figure, R.I., S.G.), Yellow Beryl (R.I., S.G., inclusions), Hessonite Garnet (optic character, inclusions), Sillimanite (optic figure, inclusions, R.I., S.G.), Synthetic Cubic Zirconia (dispersion, S.G., U.V. fluorescence), etc.

 

[pregcurious]

Thanks for the tips LD. Can I also find you on any other gemology forums?

 

[digdeep]

At this point it would be best to take the stone to a lab that can do the testing accurately so that the information and testing is correct in identifying it. It appears it could be an untreated natural yellow sapphire, but the lab will be the best way to substantiate this. Does anyone know the best (most reputable) colored stone/sapphire lab in Bangkok for this testing? Good luck Tariq! And let us know what you find out.........

 

[LD]

Thanks for the tips LD. Can I also find you on any other gemology forums?

Yes Preg - the other one! X

 

[LD]

Tariq

If I recall from various other posts you have the capability to test for RI, SG and perhaps have a spectrometer? If so you can eliminate various combinations and then decide whether you want to lab test or not. Yellow sapphires have 3 markers (lines) that will help identification if you're used to reading a spec. Sometimes it's fun to take things as far as you can by yourself as it certainly helps to educate oneself x

 

[cm366]

At this point it would be best to take the stone to a lab that can do the testing accurately so that the information and testing is correct in identifying it. It appears it could be an untreated natural yellow sapphire, but the lab will be the best way to substantiate this. Does anyone know the best (most reputable) colored stone/sapphire lab in Bangkok for this testing? Good luck Tariq! And let us know what you find out.........

AIGS in Bangkok is reputable, has excellent service and is relatively inexpensive. It's definitely fun to find out more yourself, but a lab report is a good idea as well.

 

[chrono]

GIA Bangkok would be my choice since it could be a sapphire. I am curious as to the resulting ID because the rainbow dispersion is throwing me off.

 

[minousbijoux]

GIA Bangkok would be my choice since it could be a sapphire. I am curious as to the resulting ID because the rainbow dispersion is throwing me off.

Chrono: please say more. What causes you to prefer GIA? TIA.

 

[chrono]

Between AIGS and GIA for testing sapphires in Bangkok, I believe GIA to be the "stronger" lab. They automatically test for a whole passel of things right off the bat. In terms of treatment, GIA seems to be better at detecting them than AIGS.

 

[minousbijoux]

Between AIGS and GIA for testing sapphires in Bangkok, I believe GIA to be the "stronger" lab. They automatically test for a whole passel of things right off the bat. In terms of treatment, GIA seems to be better at detecting them than AIGS.

Good to know. And for new readers, I assume part of what you are referring to is the difference in testing equipment. While both labs can test for diffuscion, the testing capabilities of LA‐ICP‐MS (GIA equipment) is greater than that for LIBS (AIGS equipment).

 

[chrono]

To clarify, GIA has found a few sapphires that AIGS tested to be unheated, as heated.

 

[partgypsy]

My first thought, is that is a very pretty stone. to me, it doesn't look like glass (I am NOT an expert).
Please let us know the results.

Thank you Roger Dery for interesting information and new terms.

 

[minousbijoux]

To clarify, GIA has found a few sapphires that AIGS tested to be unheated, as heated.

Wasn't that U.S. GIA, and not Bangkok? I thought we were comparing labs in Bangkok for some reason?

 

[Tariq wali]

13.113 wt on air
10.953 wt in water
first i would like to thanks to all friends of this forum , and also sorry for my poor english hope u will dont mind, thanks

picture definetly can not identifiy a gem here , so an idea can be given , really i learn a lot from this forum , i am not a gemologist ,being a gem lover i always need urs help .actually i was suspecious about the cutting of this gem , while i thought this is a yellow sapphire ,Thank you Roger Dery for interesting information ,thank you LD , and thanks to all .

i just did a specific gravity of this stone . may be it is Natural Scheelite according to the specific gravity 5.974 may be something else
while i am still confuse about the hardness of my gem vs scheelite .
http://www.multicolour.com/scheelite.html

http://www.thebeautyintherocks.com/scheelite-2-20-ct.html

http://www.gemdat.org/photo-1541.html

while i am going to bangkok , so i wanna test my ruby also , as i heard that more then 3 or 4 ct GIA send gem to newyork lab , while due to burmese senctions on burma GIA can ? send it to newyork or will test in bangkok if gem is more then 4 cts .

and what about the gublin OPD in bangkok , it is with same equipment facility as switzerland ?

hope people here will help me and sudjest me for better option .

 

[chrono]

Gubelin is also a very reputable lab and one I would have no hesitation to send my stones to either.