Blue Spinel Guidance

[qubitasaurus]

There was a recent post on new types of treatment in cobalt spinels

https://www.pricescope.com/community/threads/spinel-heated-and-diffused.213446/

Given how rare and expensive such a spinel will be, it might be worth making sure it has a lab report. This is the closest I have seen recently

http://sedagems.com/product/1-50-cts-rare-cobalt-blue-spinel/#prettyPhoto

But I can't see any indication of a lab report, and it's quite grey. So I am not sure I'd recommend it. Good luck

 

[Lisa Loves Shiny]

Gemfix has a close to 3 carat sapphire with faint inclusions that are listed as hard to see. http://www.gemfix.com/sapphire_blue.html#thumb

Gemfix sapphire



Freke's sapphire

 

[Marlow]

There was a recent post on new types of treatment in cobalt spinels

https://www.pricescope.com/community/threads/spinel-heated-and-diffused.213446/

Given how rare and expensive such a spinel will be, it might be worth making sure it has a lab report. This is the closest I have seen recently

http://sedagems.com/product/1-50-cts-rare-cobalt-blue-spinel/#prettyPhoto

But I can't see any indication of a lab report, and it's quite grey. So I am not sure I'd recommend it. Good luck

Def. a lab report for a fine blue COBALT SPINEL.

Be careful - many vendor use cobalt BLUE spinel - this is not the same like COBALT SPINEL and is misleading.
You can find many fine blue spinels from Tanzania with a very good color ( pure blue without the stronger grey mask of Sri Lanka blues).

A fine COBALT SPINEL a extremely rare - the Pala Gems stone I posted will be five figures I think - a 3+ ct stone - a sapphire would be much easier.

Cobalt is a very strong color agent - so only tiny amounts ( ppm ) are enough to produce this color - Fe2+ produce a blue stone to - a bit Cr3+ and the stone has purple hint with a color shift.

A cornflower blue - not to dark - 3+ ct -- from Vietnam or Sri Lanka ( Nomads offered one cushion) - very difficult to find and extremely expensive. So be careful with pfotoshopped pics, disco light and LED light - my fine but slightly greyish Sri Lanka cobalt spinels look like
Kashmir sapphires in LED light!!

 

[qubitasaurus]

Thanks Marlow, I really enjoy learning from these posts.

 

[Dioptase]

A vivid "windex blue" cobalt spinel without a gray mask is really expensive, more than a sapphire. In my opinion, these spinels blow out of the water pretty much every sapphires as well, but that's another story.

The cobalts from Luc Yen are hard to find and tend to be small as most of the rough is heavily included and fractured. Finding a large one isn't an easy quest. Not to mention that they are really coveted and sell very quickly when offered on the market.

 

[Marlow]

Think many vendor have looooong lists - many collectors want them.

My vendor for small Luc Yen cobalt spinel has only melee - the largest (!) was 0,11 ct - I would be happy with a 0,25-0,35 ct stone!!

I saw only one top blue Sri Lanka cobalt in a show, 0,30 ct for 300 EUR - I turned around and the stone was sold

 

[kelly10038]

Thank you all so much for the advice. I'm looking into a number of the stones that have been posted. Regarding budget, I think up to 3k. Could be higher but as a novice, I suppose I'm wary of getting taken advantage of. One more question - I'm based in NYC. I've looked at gemsny.com's website. Are there any other local vendors you would recommend?

 

[NKOTB]

Prima.

 

[Marlow]

Ah yes!!

Is the CC really so strong (violet!)? I have a small cushion with a similar daylight color bur no color change.

 

[Violetphoenix]

Sorry Marlow, I don't know what CC means. I'm new with all of these terms..

 

[Violetphoenix]

Marlow- I got it, CC = color change. Yes, mine does look distinctly purple under incandescent light and pale blue, periwinkle like color, in bright natural light. I also bought a pair of pear shaped Luc Yen spinels, with same shade of light blue from Brad at Gemstrader, cleaner stones, but no color change.