blue sapphire v. blue spinel

[beaujolais]

I''m looking to make a blue sapphire or blue spinel round x-prong ring. Does anyone have any ideas on the differences in look and practical matters regarding these stones? Thanks.

 

[gailrmv]

From my newbie understanding, both are a very good choice due to their outstanding hardness and durability. Spinel is less expensive (by a lot), so it depends whether that matters to you either way. You may be able to get a much bigger ring for your budget, or save money, but will it bother you that it''s not a sapphire - that''s something to think about. I have also heard that spinel can often take on a greyish hue. I know that there are beautiful blue spinels out there - they are just harder to find and will command a premium over the more average spinels. I am sure your ring will be beautiful with either gem. Have you seen LtlFirecrackers''s x prong with a sapphire? Someone else has a mark morrell with sapphire. The best spinel I''ve ever seen is matatora''s necklace (VERY old thread, you''ll have to do a search.) Probably 3 years ago. Beautiful spinel.

 

[coatimundi_org]

Spinels are generally not treated, so if that''s something that concerns you--it might be a good choice. If you were talking ruby vs. red spinel, I''d say red spinel, but in this case--I''d go for a sapphire bought from a reputable vendor. There''s more color variety to choose from, and they are easier to find. You''ll find more greyish blue spinels, but vibrant blues can be found with some searching. The price difference is considerable, but they are both durable, wearable stones.

 

[Proteus]

I rather like spinel as a replacement for sapphire. It''s a lot easier (at least I think so) to find a clean, transparent spinel for a decent price than a sapphire. Spinel doesn''t typically have the strong color zoning you see in many sapphires. Spinel is singly refractive (like garnet and diamond) so it doesn''t have any greenish dichroism like you will see in a lot of sapphires. But yes, color saturation can be an issue - spinels often are more grayish, but you can find a decently saturated blue. Cobalt spinel is incredibly rare (and expensive,) but the intensity of the color puts most sapphires to shame.

To compare the optic qualities:
Sapphire is an RI of 1.76, with dispersion of 0.018
Spinel is an RI of 1.72, with dispersion of 0.020

So, sapphire has a bit higher RI, but spinel has a bit more fire.

As far as durability and hardness are concerned, spinel wears pretty well in jewelry.
I''d say browse around and do some pricing and appearance comparisons, see what you like. But I certainly wouldn''t be afraid of owning a spinel.

 

[chrono]

I'm going against the majority today. As much as I love spinels, the blue spinels cannot compare to blue sapphires. The red spinels can pass off as rubies but not the blues. I've been searching for severals years now for top blue spinels and have yet to found any that can pass off as a sapphire. Either it has a greenish tint, gray mask, violetish hue, etc and they just do NOT hold their colour under all lightning conditions, unlike blue sapphires. The only advantage a blue spinel has over sapphires is the price and non-treatment factor. Yes, there are some cobalt spinels that might give a sapphire a run for its money, but the price of those are also very high and comparable to a blue sapphire as well.

In short, I've come to appreciate blue spinels on its own terms, and never in comparison to blue sapphires.

 

[beaujolais]

Thanks all.

Tan Dog Mom - I searched and found both of those rings & the necklace. They are beautiful and I do love the x-prong with a round sapphire.

 

[gailrmv]

Date: 8/15/2008 11:03:29 PM
Author: sonomacounty
Thanks all.


Tan Dog Mom - I searched and found both of those rings & the necklace. They are beautiful and I do love the x-prong with a round sapphire.

Cool, glad it helped! I think LtlFirecracker''s is a cushion and the other is a round. Remember that sapphires (and I assume spinels too) face up smaller than diamonds so it may be more helpful to think in terms of mm when trying to match the stone to the setting. Can''t wait to see what you get!!

 

[Proteus]

Date: 8/15/2008 9:28:48 PM
Author: Chrono
I''m going against the majority today. As much as I love spinels, the blue spinels cannot compare to blue sapphires. The red spinels can pass off as rubies but not the blues. I''ve been searching for severals years now for top blue spinels and have yet to found any that can pass off as a sapphire. Either it has a greenish tint, gray mask, violetish hue, etc and they just do NOT hold their colour under all lightning conditions, unlike blue sapphires. The only advantage a blue spinel has over sapphires is the price and non-treatment factor. Yes, there are some cobalt spinels that might give a sapphire a run for its money, but the price of those are also very high and comparable to a blue sapphire as well.


In short, I''ve come to appreciate blue spinels on its own terms, and never in comparison to blue sapphires.

Cobalt spinels aren''t impossible to find. I find that they''re nowhere near the cost of a comparable (especially unheated) sapphire, but to each his own. Yes, they do look a bit different, but they are different minerals. You can''t really expect to use them as a 100% identical replacement, but they make a fantastic alternative. I''ve always found the color shifting of spinel to be a rather nice quality, it keeps things interesting. Sapphires nearly always have some sort of zoning, dichroism or slight color shift affecting the color as well, so I don''t know that it''s really fair to compare them in that way. Sure, it''s easier to find a sapphire in a "perfect" blue, but the prices also become silly, and they''re almost always a violetish-Blue. I practically never see sapphires grade up as a true, straight Blue (and I see them on a daily basis.) A fine cobalt spinel is typically a lot closer to an actual Blue.

Another point I like about spinel: everyone seems to have a sapphire. Not that many people have a spinel. That fact give them a more unique feel. Why would you want to pass it off as something else, when you can enjoy it for what it is?

Top color sapphires also look generally fake/synthetic to me anyway.

Speaking in terms of weight versus size, spinel is about 10% less dense than a sapphire, so you''re getting a slightly larger diameter stone at the same carat weight.

 

[colormyworld]

sonomacounty asked, I'm looking to make a blue sapphire or blue spinel round x-prong ring. Does anyone have any ideas on the differences in look and practical matters regarding these stones? Thanks.

Very few spinels will have as vivid a blue as sapphires. The only exception I have seen are those sapphires sold in "maul" stores. If a spinel comes any where close the the color of a fine sapphire it will be very expensive! as it is a real rarity. I have seen prices for these type spinels at or above sapphire of equal quality. Blue spinels are quite prone to color shifts in various lighting. It is a bit like comparing oranges to apples.

Proteus feel free to share some links to those cobalt spinels. I have been looking for quite some time. The best I have seen to date although not cobalt are some blues coming out of Vietnam. The one on the right is one of these.The hue looks similar to the one in your avatar.

 

[Love in Bloom]

Date: 8/18/2008 4:22:05 PM
Author: colormyworld

Very few spinels will have as vivid a blue as sapphires. The only exception I have seen are those sapphires sold in ''maul'' stores. If a spinel comes any where close the the color of a fine sapphire it will be very expensive! as it is a real rarity. I have seen prices for these type spinels at or above sapphire of equal quality. It is a bit like comparing oranges to apples though.

I totally agree with you on this. I have seen both and consistently prefer the vivid look of fine blue sapphires. All of the blue spinels I have seen seem very murky to me, if that''s any way to describe it. Though if we''re considering purple spinel, sign me up!!

 

[colormyworld]

Lib some may say murkey. I like to think they are mysterious.

 

[Love in Bloom]

Ah, I do believe that ''mysterious'' is a better way of describing the look! Thanks CMW!

 

[colormyworld]

No problem Lib. Granted very few look much better than those blue black sapphires sold at most B&M stores.

 

[beaujolais]

Well, sapphire it is then.

Thanks all.

 

[innerkitten]

I think it''s tough to find a good blue spinel. A lot of them have gray in them or are dark. I''m sure with a lot of searching it could be done. I think spinel does red better than it does blue though.

 

[colormyworld]

 

[FrekeChild]

Personally I prefer the sparkle of spinel, but that''s just me...

 

[chrono]

I used to try to compare blue spinels to blue sapphires but now I don''t. They just don''t come close, and those that do are exceptional stones with exceptional pricing. Thus, I''ve come to appreciate and enjoy them for what they are. I like the term "mysterious". What a wonderful way to describe it.

 

[Proteus]

Date: 8/18/2008 4:22:05 PM
Author: colormyworld
sonomacounty asked, I'm looking to make a blue sapphire or blue spinel round x-prong ring. Does anyone have any ideas on the differences in look and practical matters regarding these stones? Thanks.

Very few spinels will have as vivid a blue as sapphires. The only exception I have seen are those sapphires sold in 'maul' stores. If a spinel comes any where close the the color of a fine sapphire it will be very expensive! as it is a real rarity. I have seen prices for these type spinels at or above sapphire of equal quality. Blue spinels are quite prone to color shifts in various lighting. It is a bit like comparing oranges to apples.

Proteus feel free to share some links to those cobalt spinels. I have been looking for quite some time. The best I have seen to date although not cobalt are some blues coming out of Vietnam. The one on the right is one of these.The hue looks similar to the one in your avatar.

There are several cobalt spinels on eBay, but I don't usually trust eBay that much. One of them has a lot of flaws, and has obviously photoshopped images. Wildfishgems had a nice cobalt spinel for a while, but it's sold now... so I guess posting the link is kind of silly, but just to see the color:
http://www.wildfishgems.com/inc/sdetail/5226

It was $460/ct... that doesn't seem too bad to me, but definitely not cheap. In my experience, cobalt spinels tend to throw out flashes of red dispersion. It's quite cool. Even though the dispersion is only 10% higher in spinel, I always find that faceted spinels seem to have a lot more dispersion and scintillation than sapphires do. I guess it's another reason for which spinel is mysterious.

Wildfish still has one other cobalt, but the clarity is not so good:
http://www.wildfishgems.com/inc/sdetail/5225

I agree that sapphire versus spinel is apples to oranges. Also I agree that spinel does reds better than it does blues... but don't forget that it also does insane pinks! If any of you have seen the finer mahenge spinels, they're really wild. I had the pleasure of cutting a pair of them a few years ago. I hated having to send them back to the owner

I've only ever seen one pink sapphire that rivaled the color, and it was astronomical in price.

 

[GemRite]

My opinion is blue spinel. Durability is close but I think the dispersion gives spinel a little added bonus. As well, even reputable dealers many time will not know if a sapphire has been treated with Beryllium. The will only know it to be heated. A report I read discussed this , they said ~30% of heated blue sapphires had been treated with Be. Special test is required, so many times stone want be tested for it. I am personally an all natural person. I believe a treatment beyond low heat and oiling of emeralds as being mfg''ered by man. I give a little with Aquas, Tz''s, tourmalines, zircons and other low heat treatments. When you cook them to the point of melting to reconstitute the stone. But that is another topic. Cut spinels are nice! I only cut sapphires and rubies that are untreated, I know many times the color may not be as eye popping but you know it''s natural. Spinels usually have a hint of grey tones, and untreated sapphires can as well. I fall in love depending on the color of the stone and cut. I can generally be impartial to stone type Spinels are rare and not as common as sapphires. I hope one day the lack of treatments and the rarity of spinel the price will be corrected. For now it is cheaper, which is good. Just not as well known as the sapphires.

 

[chrono]

Yes, the Mahenge spinels are really something, especially in larger sizes. It''s beautiful enough to take my attention away from the stoplight red ones.

 

[Fly Girl]

Date: 8/19/2008 5:38:31 PM
Author: Proteus

Date: 8/18/2008 4:22:05 PM
Author: colormyworld

sonomacounty asked, I''m looking to make a blue sapphire or blue spinel round x-prong ring. Does anyone have any ideas on the differences in look and practical matters regarding these stones? Thanks.

Very few spinels will have as vivid a blue as sapphires. The only exception I have seen are those sapphires sold in ''maul'' stores. If a spinel comes any where close the the color of a fine sapphire it will be very expensive! as it is a real rarity. I have seen prices for these type spinels at or above sapphire of equal quality. Blue spinels are quite prone to color shifts in various lighting. It is a bit like comparing oranges to apples.

Proteus feel free to share some links to those cobalt spinels. I have been looking for quite some time. The best I have seen to date although not cobalt are some blues coming out of Vietnam. The one on the right is one of these.The hue looks similar to the one in your avatar.

There are several cobalt spinels on eBay, but I don''t usually trust eBay that much. One of them has a lot of flaws, and has obviously photoshopped images. Wildfishgems had a nice cobalt spinel for a while, but it''s sold now... so I guess posting the link is kind of silly, but just to see the color:
http://www.wildfishgems.com/inc/sdetail/5226

It was $460/ct... that doesn''t seem too bad to me, but definitely not cheap. In my experience, cobalt spinels tend to throw out flashes of red dispersion. It''s quite cool. Even though the dispersion is only 10% higher in spinel, I always find that faceted spinels seem to have a lot more dispersion and scintillation than sapphires do. I guess it''s another reason for which spinel is mysterious.

Wildfish still has one other cobalt, but the clarity is not so good:
http://www.wildfishgems.com/inc/sdetail/5225

I agree that sapphire versus spinel is apples to oranges. Also I agree that spinel does reds better than it does blues... but don''t forget that it also does insane pinks! If any of you have seen the finer mahenge spinels, they''re really wild. I had the pleasure of cutting a pair of them a few years ago. I hated having to send them back to the owner

I''ve only ever seen one pink sapphire that rivaled the color, and it was astronomical in price.

Thanks for the links to those cobalt blue spinels!!! Awesomely gorgeous! Just a matter of time before they get discovered and the price shoots up.

 

[chrono]

Those cobalts look nice but they still cannot hold a candle to the best sapphires. I suppose it''s because they have a steely/metallic look whereas the top sapphires have that wonderful soft velvety look.