Talk:Tourmaline

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The style in this article is atrocious! Anyone making an edit or with enough time, remove all the soft commas.

The page is much improved.

Contents

[edit] Additions I would suggest

Tourmaline polarizes light when cut perpendicular to the long axis. It is both pyroelectric and piezoelectric.


Tourmaline also comes in the colors: orange (sometimes called Pumpkin Tourmaline) and purple (Siberite when found in Russia, but also found in California).

Radiation can be used to change the color (if I remember right, this was in a paper >30 years ago by an AT&T or Bell Labs researcher).

[edit] Incorrect entry of Tourmaline Refractive Index

The Refractive Index entry is incorrect, transparency is ANOTHER optical property. The correct Refractive Index for Tourmaline is 1.624-1.644. The variation is +-.005 and the birifringence is .020.

OK. Fixed per 20th ed. Dana Manual. The article text appears to be largely from 1911 Britannica article and in need of serious rewriting ... someday :-) -Vsmith 00:11, 29 Apr 2005 (UTC)

[edit] Wrong!

The whole page is wrong. 'Tourmaline' is not a mineral, and shouldn't be described as one. It's a group of minerals with similar (but not identical) properties - minerals such as Elbaite, Dravite, Schorl, Uvite, etc. So it's plain wrong to list physical properties, etc. when they vary from species to species. I don't really have time to update this now, but someone needs to kick this page around. --Jolyonralph 13:09, 6 May 2005 (UTC)


I submit that the whole page isn't wrong. Tourmaline is a mineral because it has a characteristic crystalline form. Because of its chemical complexity and variability we witness a broad range of color, perhaps more than any other commonly recognized gemstone. I have never heard anyone in Gemology refer to the "Tourmaline Group."

I agree w/ Jolyonralph, tourmaline is a group of minerals with varying compositions. Many of the physical properties are shared by members of the group but not all. The page should be revised as a group page with each of the various minerals in the group described with a section or a separate page (for the major ones). Properties in common should be discussed in the intro and specific properties amplified in each section/subarticle. See Mineral galleries] for an example discussion. I'll put it on my to do list, but ... when?  :-) Vsmith 04:05, 15 Jun 2005 (UTC)

Why not take the members of this group and treat them the way garnets and feldspars are delt with on Wikipedia? I know that this requires a lot of work from Wikipedians familiar with gemstones but a worthy task nonetheless. User:T.E. Goodwin

That's basically what I had in mind. Someday. -Vsmith 23:20, 20 Jun 2005 (UTC)

OK - finally started revising the article as a mineral group. More to do... Vsmith 03:03, 13 September 2005 (UTC)


Interesting point, tourmaline is commonly quoted on alternative sites as emitting far infrared radiation and negative ions. Perhaps some comment on such doubtful claims as these would be useful.

[edit] i have a chunk

i have this piece of tourmaline,approx. 1" diam. x 2" long, basicalliy a 2"x 2" cylinder.

 it looks pretty dark ( opaque ) looking down the axis,has blue/green/golds on the edges and has a rough "skin" that is white streaked and rough,almost as if it was a stalag-mite/tite. i got this in a little "mine your own" type place in the White Mountains of New England.Namely just off of Mt.Washington in New Hampshire/Vermont.
Can anyone advise me of this crystal?

thank you slocke3750@aol.com 24.3.178.128 16:53, 23 February 2007 (UTC)

[edit] Varieties

It should probably be noted that while the different species of tourmaline are commonly divided out by their color this is not an accurate method of distinction by any means. Along those same lines this article refers to both the species and the variety names but does not at any point make the distinction between the two, that species are recognized minerals and varieties are just general names with no regulation as to meaning Kevmin 02:08, 26 February 2007 (UTC)

[additional comment] While there are several varieties of tourmaline based on their chemical composition, such as liddicoatite, dravite, elbaite, etc, almost all the jewelry-usable material is elbaite. These are properly described by color, such as rubellite, indicolite, paraiba, bicolor, etc.

Varieties such as dravite are usually nearly opaque black, and not used much in jewelry.

The "varieties" that you reference, Dravite, liddicoatite, elbaite, etc... are not in actual fact varieties. These are separate SPECIES of minerals that are part of the Tourmaline GROUP, which in turn is not actually a mineral species itself. THe spereation of tourmaline by color is at best inaccurate. The color that a specimen my be often has little bearing as to the actual species represented. This is one of the inconsistencies that I was referring to in my original post, PS please sign your posts Kevmin 02:02, 6 March 2007 (UTC)
You are both speaking different languages. Kevmin, you speak mineralese, while Krementz speaks gemstone-ese - to use this rough analogy. In your own fields you might be correct but to foist your respective views on the article would be short sighted. Right now the article needs a bunch of expansion to tease out the intracacies of this gem/mineral group. As with any mineral/gem I would suggest developing subsections to deal with the different content needed to develop the article. Mineral details specifying species of tourmaline etc, and then a seperate section dealing with the gem varieties (that are typically based on color - ignoring the mineral species), rubellite, indicolite, paraiba, bicolor, etc. BTW I would like to confirm whether the statement made by Krementz that "almost all the jewelry-usable material is elbaite" really is accurate. I am not sure that it is. Prove me wrong though please. SauliH 07:28, 6 March 2007 (UTC)


Reply from Krementz

Gemology and mineralogy are not quite in lockstep in identification. There is an official mineral board that makes nomenclature decisions; there is no equivalent in gem-land. In gemology, tourmaline is considered a species, although, as you note that is not precisely correct. A gemologist only sees elbaite, and calls it tourmaline. There is essentially no jewelry-usable tourmaline other than elbaite. You have asked for proof (other than my 30 years in the business, which I know doesn't count for anything in wiki-land), which I will research. However, look at the posted descriptions of the other species of tourmaline, none of them even sound remotely pretty. Let me turn this around - can you document any significant usage on non-elbaite in regular jewelry?

Gemology identifies paraiba, rubellite, indicolite, etc. as varieties. They are all elbaite. The only possible non-elbaite used in traditional jewelry is liddicoatite watermelon tourmalines, which may rarely be transparent and clean enough to facet, and very difficult to identify separately from elbaite. Even so, all the samples of liddicoatite I have seen have been heavily included, and cut as slabs, not as faceted or cabochon.

I have always seen turamali defined as "mixed gemstones" in Sinhalese, as well as "attracting ashes". A quick browse with Google will show dozens of the mixed gemstone etymologies, as well as ashes.

69.141.43.74 23:51, 30 April 2007 (UTC)


[edit] Tourmaline antiquing solution for copper, bronze and brass.

Tourmaline as a solution is used to antique or darken copper, brass and bronze. It is available in brown and black and afterwards the metal should be rinsed in water before coating with Jade Oil. It would be interesting to know the chemical composition and process required to produce the Tourmaline fluid. AC 11:12, 11 March 2007 (UTC)

[edit] Rubellite

Anyone feel like dealing with the emergence of an impression amongst the ignorant that Rubellite is a kind of artificial ruby ? Maybe this is because of the common heat-treatment technique ? 86.141.92.73 21:42, 11 June 2007 (UTC)


Interesting - I had a qualified diamond-grader from Tiffany tell me in all seriousness that a heat-treated rubellite stone is an artificial ruby. There is an excellent paragraph on synthetic rubies in the Ruby Wikipedia article which mentions the idea that rubellites are sometimes represented as artificial rubies. Maybe it would be simplest and most effective to cross-reference. 160.83.32.14 11:55, 18 July 2007 (UTC)


Treatment "must" be disclosed ? Who says ? Is there an international standard operating here ? 160.83.32.14 11:17, 23 July 2007 (UTC)

[edit] Ionizing effect

It would, in my view, be of considerable importance if someone could add to the article by elaborating on the ionizing effect of tourmaline. Someone has already commented on the lack of this feature in the article, but with an air of scepticism. However, as a matter of fact one of the features of my home air conditioner is a layer of tourmaline, which the manual specifies as a constant emmitter of ions. More specifically it says:

"The air conditioner main body employs a tourmaline-coated sheet. The sheet generates negative ions around the clock. Even when the air conditioner is not running, it generates as many negative ions (2,500– 3,000/cc) as in a forest, stream or fall does, allowing you to experience them without incurring any electrical charges."

Could someone comment on this and possibly add to the article? 77.49.46.118 13:24, 14 July 2007 (UTC)

Hmmm I am not up to date with the most recent ideas/advances of ionizers.. but from my physics time, I know there was considerable doubt about ionizers, and their ability to well.... emit such a volume of Ions. I will research the topic a bit more, and yes, if it has any scientific foundation, it should have a place under industrial applications (but there are more). Nevertheless, personally I have my doubt, but that does not say much.. this is an encyclopedia after all, not an opinion page :-) to be continued... Gem-fanat 16:31, 14 July 2007 (UTC)
Did a quick check on ionizing Tourmaline. Aside from ionizing radiation which impacts the *color* of Tourmaline (science) I do nto come across anything else but stories like these: The Benefits of Tourmaline

Tourmaline NATURALLY emits far infrared energy (FIR) enlarges capillaries, purifies water, and acts like a 'supercharger', assisting in ionizing the water. Tourmaline has been researched and found to activate animal & plant metabolism http://www.allnaturalwater.com/detail.php?prodid=95. SImilar stories elsewhere. I do not see any scientific proof to substantiate the fact that Tourmaline shows Far Infrared Radiation, nor that it would purify water by itself and even less that it would activate my metabolism (or that of my dog). If you have a credible source I'd love to see it. Gem-fanat 16:44, 14 July 2007 (UTC)

I think it is useful to point out that the issue here is not whether tourmaline has any healing effects, or whether it has the ability to purify water, or anything like that, but whether it emits ions or not. What this ionization does for anybody is, from what I understand, a far more complicated issue, but besides the point here. The above excerpt is taken from the manual of a Mitsubushi air conditioner. Therefore, I would expect that, since one of the global manufacturing giants is advertising this information for one of its products, this ionizing effect is true. However, it would be nice if someone could positively provide this information and write something about this.
It should also be noted that this effect is not supposed to be anything close to what an ionizer does. From what I understand, although I am no expert, tourmaline is not forcefully charged to produce ions. It is naturally mildly charged. So, for example, tourmaline cannot produce ozone as part of its ionization (again, as far as I understand).
And just to make this point clear, no I am not working for a global manufacturing giant, I just bought this air conditioner and was wondering what it is it actually does!  :-) 77.49.28.193 20:41, 17 July 2007 (UTC)
It does nothing, pure quackery. Tourmaline maybe piezoelectric and thermoelectric, but the effect is minute and it only happens if tourmaline's temperature changes or it is squeezed. If nothing is done to it, it has no charge at all. There are modern artificial (piezoelectric and thermoelectric) materials that are 100 times more powerful, but tourmaline just sounds better then Sr0.5Ba0.5Nb2O6. --Diamonddavej 01:27, 25 August 2007 (UTC)

[edit] Here is a chunk to review about Tourmaline...

There are now patches TRMX-2i that the Chinese have developed to detoxify the body. They are made with 60% Tourmaline and "emits negative ions on average of 1300 ion/cm3. Does anyone know more about the holistic use for Tourmaline? enviromentalover~ —Preceding unsigned comment added by 74.128.191.224 (talk) 11:53, 5 January 2008 (UTC)

In order to emit ions, electrical or kinetic energy must be absorbed. Other than radioactive isotopes, no material is capable of emitting ions without added energy.

The detox patches may form ions when sweat droplets dissolve ionic chemicals in the patches. However that is not emitting ions, it is dissolving. Like the "liquid tourmaline" mentioned above, this dissolved chemical may change color, probably due to chemicals contained in the patch, possibly even reacting with the sweat. The detoxifying foot patches are pure quackery, you can wear warm socks and cause your feet to sweat without needing a chemical reaction to show "proof" that detoxification is occuring. All the detox patches do is absorb sweat, and change color in response to the absorbed sweat. Georgedotcom (talk) 19:29, 22 April 2008 (UTC)

[edit] Correction to Chemical Formula

The end member formulas do not reflect the general formula. It seems to me the general formula should at least have a Si6

XY3Z6T6Si6O18(BO3)3V3W

I don't know if the rest of it is best represented perhaps it should be X Y Z Si6O18... Where some of XYZ are polyatomic ions and can also be vacant. Hwttdz (talk) 06:02, 8 January 2008 (UTC)