Post subject: The glow like qualities of flawed tourmaline.
Posted: Tue Mar 19, 2019 3:47 pm
Gemology Online Veteran
Joined: Thu Sep 25, 2008 10:33 am Posts: 840 Location: Mars PA
In a recent post I addressed how to try and minimize the impact of flaws on the beauty of faceted tourmaline. (I recently had great success with a pink tourmaline that ended up being a round with a flaw perpendicular to the table. Face up it is so bright and flashing, you can hardly see the flaw by eye.) But are there any times when flaws are a positive force in producing beauty in tourmaline? Cats eyes cut from tourmaline loaded with growth tubes is the only example that probably comes to mind. But we have to go deeper to get to the heart of the glow like beauty that tourmaline can display.
To start out everyone probably has heard of Kashmir sapphire and its highly sought after soft look caused by inclusions. And if you ever get to see the Tourmaline copy of EnglishLapis, there are pictures of a crown that has a rubellite for a center stone. Reading about this ancient treasure leads to the assertion that radial flaws (like we see in many tourmaline) enhanced the beauty of the rubellite. The next bit of support for the right kind of flaws, helping to produce the beautiful glow like quality in tourmaline comes from a pile of Afghanistan tourmaline. It was a large pile of clean crisp crystals that were in the paraiba like color range of Paraiba tourmaline. At $100 a carat it was not cheap material and I was looking for one exceptional keeper. So many choices and so little money can cause consternation, but then I saw her. (All my really beautiful gemstones are female.) She probably came from the same find, but there was a certain level of glow like quality that the other crystal did not have. On closer examination, I could see that see was filled with minute inclusions, but no flaws. And her surface was rougher than the rest of the lot and I returned her to the pile. But I couldn't keep my eyes off of her. When it comes to tourmaline rough I am a gambler and so she came home with me. ( My host said, just after I bought her, that he would have purchased her if I had not gotten the prize.) I don't know exactly how the rest of the pile of tourmaline would have turned out, because I only bought her, but my gambled paid off in spades.
I have other examples of included Afghan tourmaline in the blue green range of colors that have a more pronounced glow like quality because of inclusions, in my opinion. And some of my paraiba type gemstones are right in there with the enhanced glow like qualities from inclusions. In fact they can be the best of the lot, but it is not a sure deal with inclusions. I have not seen enough cuprian tourmaline from around the world up, front and personal, to judge their inclusions, but I have one particular yellowish green gem that has a web of inclusions that uniformly help fill the dear with a great glow like quality. Other clean cuprian tourmalines may be brighter, but she has a better presences.
I can not give any more insight, as too why some tourmaline responds so well to inclusions and others do not. You have to use your eyes. I cut the stones to produce the best gem I could without regard for their inclusions and I certainly would take a gamble on included rough that shows me the" look" again.
Post subject: Re: The glow like qualities of flawed tourmaline.
Posted: Tue Mar 19, 2019 7:55 pm
Valued Contributor
Joined: Tue Mar 27, 2012 10:15 am Posts: 352 Location: Cary, NC
Bruce,
Awesome story and I had never heard of the differences of Kashmir Sapphire (looked it up and it was a fascinating read) versus others.
However, back to Tourmaline, are there any particular stones in your collection pictures here that you believe showcase how a flaw turned into a plus when cut? Would love to see the results of such a find and the final outcome.
As still a rank amateur, I still struggle with how to best orient a stone for the best color, yield, Etc. and usually just grab a big enough piece and begin hogging away.
My thanks,
_________________ Bob Hodges
Faceter: When turned into a zombie, they stumble around crying "roooouuuuggghhhh"
Post subject: Re: The glow like qualities of flawed tourmaline.
Posted: Tue Mar 19, 2019 8:15 pm
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
Except, because of some unique occurrence that provides collector interest, I don't see flaws as adding to stones generally.
However, there are inclusions that can add a great deal to stones. In fact these inclusions are often integral to the stone. Things like Rose Quartz, many of the chalcedony inclusions, star stones, chatoyant stone, iridescent stones silk in Ruby and Sapphire that add texture and glow as Bruce is describing.
I think it is an important distinction between inclusion, which can be a positive feature, and a flaw that has a negative connotation.
Post subject: Re: The glow like qualities of flawed tourmaline.
Posted: Wed Mar 20, 2019 12:10 am
Gemology Online Veteran
Joined: Thu Sep 25, 2008 10:33 am Posts: 840 Location: Mars PA
Thanks for the comments. I took sometime to think before exposing my growing conclusion that something physical, not just chemical, is enhancing the glow like quality of some tourmaline. I think that flaw can be used for anything that makes a crystal less than perfect in the most general case.. I think that inclusions should have a different chemistry than the crystal they are in. And I really don't like using either one when it enhances the beauty and interest in a gemstone. So what can we like and agree on "naturals"? It is fine with me
It would be fascinating to see if the treatment of Paraiba with the commercially available epoxy designed for tourmaline ( same index of refraction as tourmaline) effects its glow like qualities and commensurate value. It certainly would be a hard one to call because the glow like quality is not in the accepted definition and there are no standards except an experienced eye.
Now for a couple of beauties. If you go to my site BruceFryTourmaline.com and search for numbers 148 and 771 you will see the best examples of what this post is about. 148:
771:
Two more tourmalines with more naturals, but a distinct glow like property that might be helped by their poor crystal are numbers 598 and 588. 598:
588: All of them are in the blue green to yellowish green area of the color wheel. Only number 148 is cuprian and could be considered paraiba type. 148:
Finally the ideas in this post are just my observations and my speculations. I can not blame anyone for misleading me this time. Please do not ask me for my credentials for I have none, but I have looked at a lot of tourmaline critically
Bruce, please link to these stones. I am having trouble figuring out how to browse by number on your site. As to added value, let's not forget the most famous inclusion of all:
Post subject: Re: The glow like qualities of flawed tourmaline.
Posted: Wed Mar 20, 2019 9:31 am
Gemology Online Veteran
Joined: Thu Sep 25, 2008 10:33 am Posts: 840 Location: Mars PA
Thanks for showing me that I access my site differently than GO members from the icon on the left side of opening page marked Bruce Fry Collection.
I really don't know how to link the numbers to search for the gems, but here is an easy way to see their pictures.
Click on the icon on GO.
Click on the Tray icon at the top of the page that opens on my site.
Click on the correct tray. Now each tray has 50 stones so the first 50 stones are in the first tray and the next tray has numbers 51 to 100 etc. (#148/tray 3, #588/#598 tray 12, #771/tray 16 for the gems in this post)
Click on the label under the picture with the correct number. You can find the number by putting your cursor on top of one of the small pictures.
I think you can easily see the gem's structure in the full screen pictures, but picking up the glow like quality is very difficult, if it is possible at all. I am no photographer, these are Jeff Smith's pictures, but the few pictures on the web, that seem to show at least some of the glow like qualities, look over exposed to me.
I treasure the tourmaline!
In addition, I have written more details about the gems on other parts of my site. Please look around a little and enjoy.
Thanks Barbra! I was thinking of doing it when I got on my PC, but I have been sick in bed this week so I didn't get to it. It definitely helps understand the post better. No doubt a bit of translucency helps with glowiness. Gem silica somes at it from the other direction, having to push towards sufficient clarity to get that glow rather than needing some silk or whatnot to tamp clarity down a bit. But once you're in that zone you can get some very impressive effects.
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