Talk:Quartz

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[edit] Origin of "Quartz" in References

The reference to "Queensland University of Technology Origin of the word quartz" is broken in that there is a password requirement to get into QUT—consequently it is useless! Linmhall


Quartz is included in the 2007 Wikipedia for Schools, or is a candidate for inclusion in future versions. Please maintain high quality standards, and make an extra effort to include free images, because non-free images cannot be used on the CDs.

Tensile strength: 48.3 MPa

Pa = Pascals?


Pa = pascal(s)

S.

There is some controversy over density of quartz. Most references I've found say 2.65 g/cm3; see: [1] for details - Waveguy

[edit] Something is missing

I was looking over this article and found that the texture of Quartz is not included. I know that this is a small detail, but I believe it is, nevertheless, important. I also found that texture is not included in any other article about a type of mineral. Can someone please fix this problem? I am not entirely sure what the texture of Quartz is, so I don't want fix in case it is wrong.

[edit] Abundance of Quartz in crust

Quartz is a bit of a pain to write about. It's the most common mineral on earth, and occurs in so many different forms. The various names are used to mean different things in different contexts, and even then it's rarely rigoursly consistant.

I'll try and point out some of the range of applicability of the various names, and various applicable names.

Oh, and that density listed is not actually for quartz. It's for fused quartz, which is a glass - unlike every other type of quartz. I suspect that confusion is inevitable whilst it is shown on the main page for quartz.

Syntax 02 Jan 2004

Actually, quartz is not the most plentiful mineral on earth; that honour goes to plagioclase. I know what you're thinking: sediments (5% of earth's crust) are ~30% quartz, and granite-metamorphic rocks (~30% of earth's crust) contain about 10% quartz. Right? But feldspar is the predominant mineral in granites (at ~60% either plagioclase or orthoclase) is abundant in metamorphic rocks, is also present in sediments, and unlike quartz, occurs widely in the mafic and ultramafic rocks of the oceanic crust. So, bzzzt, quartz is evicted from the island. Rolinator 04:55, 7 February 2006 (UTC)
...although (just for fun) it does specify "continental crust" in the article.  :) By the way, for my own...er...interest, do you have a reference for your back-of-the envelope calculation? It sounds very much like you just whipped it off yourself (although good for you!) but if you have a ref that would be great. I have seen other numbers cited in German literature. Cheers,Rickert 07:09, 9 February 2006 (UTC)

[edit] Citrine

Although most citrine occurs naturally, most is the result of heat-treated amethyst.

So, what is true about most citrine? Is most citrine natural, or is most citrine made from amethyst? Or is it natural-but-derived-from-amethyst-originally? This could stand to be reworded to be less confusing. -- pne 14:12, 30 Apr 2004 (UTC)

Fixed. Looks like that was a holdover from an wording change. Syntax 22:36, 1 Jun 2004 (UTC)


[edit] Pleochroism

It's obvious that author of this article doesn't understand the meaning of pleochroism. Quartz has absolutely no pleochroism. I'll fix it. Siim 15:51, 7 May 2005 (UTC)

[edit] What is the difference between Quartz and glass?

I know that glass is amorphous SiO2, is the difference just in a macroscopic perspective of how the crystals are arranged, or is glas SiO2 non-polar while quartz is polar hybridization?

I'm not sure what you're asking here - do you want to know the difference structurally, or how to tell the difference? If you're talking identification, the best way to tell for sure is to chuck it under a petrology microscope and check to see if it's isotropic or not. If you're talking structural differences, well you're right - glass is amorphous at the atomic level - no regular lattice at all. Weebs 20:16, 15 October 2005 (UTC)

[edit] History of Quartz

"The exact date, place, and creator of the quartz oscillator are unknown to the public, as this information is classified. It is believed that it may eventually become public as the aftermath of the Cold War wears off"

- Walter Guyton Cady created the first Quartz crystal resonator along with other colleagues at Wesleyan University in Middletown, Connecticut in 1921
- George Washington Pierce also help future work in quartz oscillation by designing different types of quartz oscillators, 1923
- Warren Marrison, a telecommunications engineer developed the first quartz clock in 1927 based on Cady and Pierce's work at Bell Telephone Labratories

http://www.hrw.com/science/si-science/chemistry/careers/quartz/inventors/before.html

—Preceding unsigned comment added by 69.170.54.75 (talk) 23:22, 24 September 2006
Thanks, I have modified the article based on your reference. Vsmith 00:02, 25 September 2006 (UTC)

[edit] History

History The name "quartz" comes from the German "Quarz", which is of Slavic origin (Czech miners called it křem (should be Křemen, of I am not mistaken). Other sources insist the name is from the Saxon word "Querkluftertz", meaning cross-vein ore.

[edit] Crystal system -- hexagonal or rhombohedral?

The crystal system of quartz is rhombohedral according to fr:Quartz (minéral) (well I assume that's what "rhomboédrique" means). And sure enough, the Rhombohedral crystal system article does mention quartz as one example. Meanwhile, quartz isn't mentioned anywhere in the Hexagonal crystal system page. So is this article wrong in saying that quartz has a hexagonal crystal structure, or do hexagonal and rhombohedral mean the same thing? -- Sakurambo 桜ん坊 21:46, 5 December 2006 (UTC)

I went to the Wiki Quartz entry to look up synthetic quartz. The reference to hexagonal or six-sided jarred me. I had been through this before. Trigonal can arise out of cubic systems. Other piezoelectric crystals, perovskites for example, do that. Above the Curie temperature they are cubic and isotropic. Below the Curie temperature, the lattice distorts into the trigonal form and the crystals and become ferroelectric. If you were to look along a body diagonal of a cube, you would (orthogonally) project a hexagon. It is clear, however, that there is no six-fold symmeyry.

Hmm, i am not sure. I have a very reputable source here that says quartz is actually in the Trigonal - Trapezohedral system.... so i will have to do a little research and get back to this article. I always was taught it was hexagonal though. -- User:Chazparky 14:28, 17 December 2006

My copy of Klein - Manual of Mineralogy 20th ed, places quartz in the hexagonal system - but, according to the classification used therin, trigonal is part of the hexagonal system - and that is the way I learned it back in basic mineralogy (6 crystal systems with trigonal or rhomohedral as a part of the hexagonal system). Now for some detail: high quartz is hexagonal (class 622) whereas low quartz is trigonal (class 32). So I'd say some mention of this needs to be in the article for clarity as Wiki separates the trigonal from the hexagonal. Vsmith 00:33, 18 December 2006 (UTC)

I've got a copy of a fairly basic geochemistry textbook that says quartz's crystal system is hexagonal. It would help if someone could get a picture of the molecualr structure, especialy since its a pretty basic silicate mineral. -- User:Jason McConnell-Leech 14:54, 7 January 2007

Quartz is trigonal, also called rhombohedral, which is a sub-category of hexagonal, as Vsmith says. Klein/Hurlbut or Dana are appropriate references if one is needed. Kinda wondering why all the discussion about it, yet no change? My copy of Klein is in a box somewhere right now, but maybe I'll dig it out tonight.Olneya 22:50, 29 March 2007 (UTC)

I've removed the "Hexagonal" from the crystal system info for the sake of clarity. Following the link to the rhombohedral wiki will provide the information that rhombohedral/trigonal is a sub-group of the hexagonal system. I'm assuming it doesn't need its own ref, as there's a general ref to Klein/Hurlbut, and the info will be found there along with pretty much everything in the info box. --Olneya 03:50, 30 March 2007 (UTC)

[edit] Flashing quartz Ute rattles

See Triboluminescence#Uncompahgre_Ute_Indians

Is the flashing caused by triboluminescence (cracks in the crystal structure causing electrical discharges from the triboelectric effect) or from piezoelectricity (deformation of the crystal creating voltages and causing electrical discharges, like piezo ignition)? See Talk:Ute tribe#Comment on piezoelectricity for discussion. — Omegatron 04:03, 26 November 2006 (UTC)

[edit] Ruby Quartz

Looking around the net I have found that the only place that ruby quartz displays the properties listed here is in the X-men comic book universe. Ruby quartz does actually exist, but with different properties. I'm not sure how to make this change, but I thought that it should be brought the attention of those who know. Thanks 68.102.208.72 04:37, 13 December 2006 (UTC)

[edit] Phantom quartz

For consideration as either a stand alone article, a Wiktionary entry, and/or a section in a longer article ... Recently added to Phantom, Phantom quartz, in response to the use of the term 'phantom' in the appropriate context in Herkimer diamond. Found external reference: http://rockhoundingar.com/quartz/types.html and http://rockhoundingar.com/quartz/phantom.html. --User:Ceyockey (talk to me) 01:07, 18 March 2007 (UTC)

[edit] Georgia's state gem...

Could someone possibly put in a reference to Quartz being the State Gem of Georgia? Probably in History, but maybe in a whole new area... ROBO 00:46, 16 May 2007 (UTC)

[edit] "quartzes" crystals

“ in fact these oscillators are often simply called "quartzes" or "crystals". ”

I removed the above as unlikely and uncited. Correcting nonesense 19:50, 31 August 2007 (UTC)

I don't know if it's correct. However, I've seen people called those crystal oscillators "crystals" (never seen "quartzes", though). Warut (talk) 11:45, 29 December 2007 (UTC)

[edit] Synthetic quartz image

Kevmin removed the synthetic quartz image by asserting that IMA has rules that man made materials are not minerals. I totally disagree with that and will bring back the image because this article is not meant to talk only about natural quartz. In fact, the image was placed next to the text that described synthetic quartz. Why removed only the image? Hopefully, this is not related to those recent anonymous edits on this image. Warut (talk) 22:59, 28 December 2007 (UTC)

While we may not like some of the rulings that the IMA has made since its creation in 1956(?), they are the overseeing body for mineralogy with the same authority as the organizations which oversee astronomy, chemistry etc.. and thus we are stuck with them until they are changed by the IMA itself. The picture was removed in part because of the trouble with the IP but also because it and the associated paragraph should be merged with the Chemistry article for synthetic quartz= Silicon dioxide. While a small section can be retained, most of the information is already present in Silicon dioxide or should be transferred.--Kevmin (talk) 00:19, 29 December 2007 (UTC)
I have updated the paragraph slightly with a link to the Silicon dioxide article, and have changed my opinion on removing the picture. Hope this is OK--Kevmin (talk) 00:26, 29 December 2007 (UTC)
Thanks for your explanation. I'd never known before that the use of the word "quartz" is actually limited to the naturally-occuring one since I often see things like quartz oscillators in clocks and quart window on EPROM. (Can someone else confirm this?) I had thought that its usage is like that of diamond, i.e., we can call anything diamond as long as its chemical composition and its atomic arrangement are those of diamond no matter how it's formed: natural or man-made. Warut (talk) 11:38, 29 December 2007 (UTC)