Question about blue spinel

[colormyworld]

I would like to know how rare spinels are with a decent blue hue in a medium to medium dark tone.

 

[Edward Bristol]

Doug, welcome,
Of course the super excellent blue spinels are always rare as they are defined by being the top end and thus rare. But you can get pretty nice blue ones in M50 to MD80 starting from somewhere at $70+/carat.
however, very rare is cobalt spinel, in fact so rare that is hard to find any at all.
You will see that many here, like me, are spinel fans and you will find quite a few past discussion on the topic.

Edward Bristol
www.wildfishgems.com

 

[colormyworld]

The reason I ask is because just about all I see are so gray that it is hard to see the blue from more than four feet away. I guess I mean with good saturation.

 

[Edward Bristol]

Try and look at some ultramarine blue ones. So good. Not to imitate sapphire blue, but as a blue speciality on their own.

Edward Bristol
www.wildfishgems.com

 

[colormyworld]

Thank you for your response Edward. I was just wondering about how rare a spinel like this is.

 

[colormyworld]

This is a 9.59ct natural spinel. I have had it looked at by gemologist. He first checked the R.I and then checked for ADR. Both led him to believe it is natural. I am wondering how rare a stone with this tone, hue, and saturation is.Thanks in advance Doug

 

[Sagebrush]

Colormyworld,

Your stone, what I can see of it, appears to have exceptional color, hue/saturation/tone.

Blue spinels, in my experience, usually have a distinct gray secondary hue or mask. The one exception is the legendary cobalt blue. Very rare. The only other was a synthetic.

ADR is not an infallible test and the RI difference is only a single point.

 

[pad3006]

wow that is some rock, that is gorgous. The cut of it is beautiful. Congrads on that stone.

Phil

 

[colormyworld]

Thank you for your reply Richard. Do you have any suggentions as how to determine if natural or man made? I also have two other spinels about the same class. Two do have a very slight gray cast to them.

 

[Richard M.]

Date: 9/2/2005 5:00:01 PM
Author: colormyworld
This is a 9.59ct natural spinel. I have had it looked at by gemologist. He first checked the R.I and then checked for ADR. Both led him to believe it is natural. I am wondering how rare a stone with this tone, hue, and saturation is.Thanks in advance Doug

Doug,

If you have any question about the stone have your gemologist look at it with a Chelsea Filter. If it''s a flame-fusion synthetic with cobalt added, the stone will appear strongly orange to red depending on the depth of color. This test is diagnostic but requires some judgment/experience because naturals can exhibit some similar color but not as strikingly. I can almost always tell a flame-fusion blue spinel by eye simply by checking for strong flashes of red either from crown or pavilion in a strong light. I do confirmatory tests, of course, but that''s a powerful clue.

The absorption spectrum of flame-fusion cobalt-added stones has broad bands in the orange, yellow and green. The central band will be the widest. Natural spinel shows strong bands in the blue region where cobalt has no bands to show. This should tell the tale on flame-fusion.

Remember, flux-grown red and blue synthetic spinels are now coming out of Russia. I haven''t had any for testing yet but I know the red color is very difficult to separate from natural. Rough -- so far as is known -- seldom exceeds 5 carats, reducing the liklihood your large stone is that material.

Beautiful stones!

Richard M.

 

[Sagebrush]

Colormyworld,

Have never seen that many fine natural blue spinels together in a picture or anywhere else. Makes me suspicious. Suggest that if your gemologist is not conversant with spinel, Richard M might be the guy to send them to.

 

[colormyworld]

Thank you both Richards for your replies. I look foward to your reply from my e-mails.

 

[valeria101]

Date: 9/3/2005 7:39:31 AM
Author: Richard W. Wise

Have never seen that many fine natural blue spinels together in a picture or anywhere else.

Yes sir! Same here.. There is no way to perform proper tests on a picture and the scenario is way too goo to be true.

Als, the secind picture lools as if the background is photoshoped in and possibly the pictures of the stones have been overlayed via such post processing as well.

 

[colormyworld]

I assure you that these are not "photoshopped" other than cropped. I have them on a table in my back yard. I agree ,there is no way to preform tests on the picture I have e-mailed Richard M about confirming the nature of these stones. Please don''t assume the worst until I have been given a chance to have the tests done. I am not an expert but a GIA trained gemologist has looked at them. The sources I aquired them from has been very reliable in the past. These are all spinels.

 

[belle]

amazing color! i would love to see more pics

 

[colormyworld]

I make a copy of the image so I can crop with out losing the original. I must crop to get the file down to a size that will upload. I guess I should take the suspicion as a complement as that tells me that they look that good!

 

[colormyworld]

Sorry for posting the same pic twice I thought it was this pic which was taken at a slightly different angle.

 

[colormyworld]

I use this table because I like the way it adds intrest to my pics.

 

[colormyworld]

I do not have enough computer smarts to pull off what valeria suggests

 

[colormyworld]

It sure is easy to take pot shots at my integrity and then B A I L!!!!!!!!!

 

[widget]

Oh my gosh.....I don''t think anyone was questioning your integrity!!!!!

Here in the Colored Stone forum, a lot of time is spent looking at and posting pictures, discussing color, lighting, photography, etc etc....almost NEVER with ill will intended!

I think this is a misunderstanding and I hope it doesn''t deter you from participating in the forum and sharing your treasures..

widget

 

[strmrdr]

Ok I can see why Val thought they might have been photoshoped.
At first glance it looked like she might be right.

When I blew the images up and looked at 10x I dont think they were photoshoped.

The background you used for the photos is why it looks that way.

As to the question if they are natural or synthetic I cant say but if they are natural you are one lucky person to have that many great stones in your collection.

 

[Richard M.]

Everyone FYI,

I''ve already PM''d colormyworld but for clarification:

I don''t offer professional gemological services. I had some thoughts for testing that work for me personally and posted them as suggestions for his gemologist if needed. I also recommended the services of a full-time gemologist/appraiser who posts here regularly, as well as the highly-regarded professional lab I use.

Richard M.

 

[Richard Sherwood]

Wow. Gorgeous blue.

With the slightly possible exception of the grayish blue stone on the left (in the 3 blues picture), that saturated a blue is usually not seen in natural spinels.

I'd be surprised if they were natural.

How much did you pay for them? That's always a good indicator. If they were inexpensive, they're probably lab created. Natural spinels with that kind of color would be pretty pricey.

 

[Richard Sherwood]

Stick around, by the way. This forum is a lot of fun, and gives you plenty of practice at not taking things personally. Good soul growth.

 

[spinel]

Hi All,

I worked with piles of spinel rough this year and found only two really nice pieces of blue spinel. As a matter of fact, nice blue spinels are rare, more rare than red spinels! FYI, spectrum analysis confirmed the presence of trace of cobalt in the spinels.

This one is a beautiful blue spinel rough, very pure blue. Unfortunately I don't have the photo of the cut stone.

 

[spinel]

This spinel is a little bit gray.

 

[colormyworld]

I got my gemologist to grade two of my spinels saturday. The first one is 10.44 cts 13.30x11.95x8.3 d %=69.4 tab % =50 polish= good ms= vg color= vs pb6/3 vvs. the other is 9.60cts 12.64x12.05x7.7 d=62% table=50% polish good ms= good color bp 7/4 I most likely took valeria101 a little hard. I have moved on I really do like the this forum. thanks