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 Post subject: Question about Kashmir Sapphire
PostPosted: Tue Jan 12, 2021 3:30 pm 
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The Kashmiri sapphire is a much prized and sought after gemstone. However I would like to raise a query on this forum that I am not clear about.

The prized Kashmir sapphire often mentioned in literature is from the Indian part of Kashmir. But sapphire is also found on Pakistani side of Kashmir, which includes the area of Gilgit-Baltistan (GB), that lies along the same geological area as the area from where sapphires are mined in Indian Kashmir. On this forum, I had earlier shared a picture of rough dark blue/purple sapphire found from GB. Similarly, Pakistan government's mineral department as well as few websites mention the location of mines in GB from where sapphires are mined (like https://www.mindat.org/locentries.php?p=14322&m=3529). These sapphires come in pin color too.

My query relates to differences between sapphires on Indian and Pakistani Kashmir side, especially the prized blue ones. Or are they pretty much the same as far their geological and chemical makeup is concerned? Does anybody have info on this matter?

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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Tue Jan 12, 2021 5:15 pm 
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They are totally unrelated geologically. The Pakistani material is wonderful and has produced some amazing trapiches as well, but doesn't have the same value as the Indian material.

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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Tue Jan 12, 2021 8:19 pm 
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The stones that can be proven to be of the old Indian Kashmir deposit carry a hefty price premium.

The determination of the origin of blue sapphire is an interesting topic. It is not an exact science yet.

https://www.gia.edu/gems-gemology/winte ... ermination



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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Wed Jan 13, 2021 8:28 pm 
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As others have mentioned they aren't the same geographically. Chemically, sapphires in general have a very similar chemical structure, otherwise they wouldn't be sapphires. The impurities in corundum give it the different colours (Iron for sapphire, chromium for ruby, etc.).

As to the chemical difference between the regions I wouldn't know. I would suspect labs like GIA and others that have libraries of gems scanned would be able to answer that question better.

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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Thu Jan 14, 2021 3:42 pm 
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I bought a parcel of sapphires maybe 24 years ago from a geological supplier in London:

Image

They were labelled as coming from Montana, USA, and at the time I had no reason to question it, as I didn't know much about the appearance of sapphires from various locations. However, after showing that photo to gemmologist Alan Hart, his immediate thought was that they are old stock from the legendary mines in Indian Kashmir. Certainly, they look just like pics online of sapphire rough from there.

I'm hoping once this pandemic has fizzled out I can actually get him to look at them in person.


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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Fri Jan 15, 2021 6:13 pm 
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Speaking as someone how has found a lot of sapphires in Western Montana, and who has seen a lot of Yogo Sapphires from Eastern Montana - those don't look at all like Montana sapphires.


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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Fri Jan 15, 2021 7:19 pm 
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Agree, I have seen, managed the treatment treatment and cutting of hundreds of thousands of carats of Montana Sapphire from various deposits and never seen any that looks like that, from any location.

The white remnants of what looks like marble/limestone/some form of calcium carbonate, would seem to indicate a metamorphic sapphire deposit. The Montana Sapphire is Basaltic in origin.
Try dropping a little HCL on the samples and see if the fizz.

At first glance it looks like some of Afghanistan (Kashmir but not Indian) Sapphire rough that I have seen before.


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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Sat Jan 16, 2021 6:01 am 
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1bwana1 wrote:
Agree, I have seen, managed the treatment treatment and cutting of hundreds of thousands of carats of Montana Sapphire from various deposits and never seen any that looks like that, from any location.

The white remnants of what looks like marble/limestone/some form of calcium carbonate, would seem to indicate a metamorphic sapphire deposit. The Montana Sapphire is Basaltic in origin.
Try dropping a little HCL on the samples and see if the fizz.

At first glance it looks like some of Afghanistan (Kashmir but not Indian) Sapphire rough that I have seen before.


I know what you mean about the Afghanistan sapphires, but they are slightly different. The white stuff is clay-like, and may be kaolin from the decay of feldspar. Under a loupe at least one of the crystals has what looks like an attached tourmaline crystal, of a dark brownish-green colour. The geological supplier I bought them from (Gregory, Bottley and Lloyd) had a lot of old stock going back to the 19th century. There was probably a label mix-up with the location.

BTW Alan Hart isn't the only one to suggest Indian Kashmir origin. Quite a while back I showed gem dealer Chris Cavey these sapphires and he immediately also said "Kashmir". At the time I didn't believe it, but after doing more research and communicating with Alan Hart it does seem to be the most likely place of origin. I'd like to get a more definitive answer in the near future.


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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Sat Jan 16, 2021 4:19 pm 
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Send a piece to Chris Smith at AGL.
He will "slam dunk" the origin in a flash.


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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Sun Jan 17, 2021 3:07 am 
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@1bwana1 Thank you for the detailed paper on Sapphires. @Nick_G, seems like you've hit a goldmine!


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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Sun Jan 17, 2021 8:54 am 
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Does Indian Kashmir tend to produce pink stones though?

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 Post subject: Re: Question about Kashmir Sapphire
PostPosted: Sun Jan 17, 2021 9:14 am 
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Barbra Voltaire, FGG wrote:
Send a piece to Chris Smith at AGL.
He will "slam dunk" the origin in a flash.


Thanks Barbra. I'm in the UK, so I'd rather have it looked at by someone domestically. Alan Hart was intrigued enough to want to see the sapphires in person, it's just having everything coming together to make it happen.

Stephen Challener wrote:
Does Indian Kashmir tend to produce pink stones though?


Yes apparently a small percentage (something like 1-3%, I can't remember the exact figure) is pink or pink colour-zoned.


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