Talk:Granite/Archive 1

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

Removed

Removed the following from the Uses: Antiquity section as it appears to be irrelevant to the article:

Nevertheless evidence indicates steel production in East Africa around 1400 BC (see [1] & Iron age: The Iron Age in Africa and India). The Iron Age in Ancient Egypt has been shown to have begun no later than 4000 BC (see Iron Age), and Egyptian ruler Tutankhamun died in 1323 BC and was buried with an iron dagger. Hardened steel has a Mohs hardness of 7 and up ([2]). Evidence of shipbuilding in Ancient Egypt dates to circa 2500 BC (see Ancient Egypt: Timeline of Achievements).

As footnotes, Professors Harrell and Lazzarini and Mr. Bruno (at E4, E16, I1, I12) also discuss ancient Egyptian works containing quartz and comprised of basalt (E15).

Vsmith 02:18, 21 Jun 2005 (UTC)

Removed dolerite as it is a mafic rock with little quartz and thus not harder than granite as was indicated. The reference given doesn't say that. In addition removed sentence about hardened steel, the Egyptians were in the iron age, but don't see a reference for hardened steel other than the uncertain material above. -Vsmith 02:37, 21 Jun 2005 (UTC)

See User:Mark Dingemanse/Roylee for more information on the strategy of the person who added this, and who is trying to edit a web of Afrocentric fringe theories and original research into Wikipedia. Any help welcome in screening the edits of this person. — mark ✎ 29 June 2005 13:34 (UTC)

Rejiggered this. Salient points for which I particularly would not like to see reversions:

• It is inappropriate to use the Mohs scale of hardness to describe physical properties of rocks. This is for minerals only.
• What is "an interesting proportion of plagioclase"? Bad wording; so I hunted out the QAPF diagram. Also, removed poorly worded unscientific stuff about "some proportion" of this and that, and the bit on monzonite being plag>orthoclase, because it's not; look at the QAPF diagram. Monzonite is <5% quartz.
• Added in something on what granite looks like, and how it outcrops, etcetera.
• Added in a section on granite emplacement mechanisms. Pretty basic, but I think that his issue deserves its own page anyway, for all plutonic rocks including ultramafic intrusions, etc.
  

Much better, I think. Rolinator 02:02, 26 January 2006 (UTC)

Removed a comment in the opening paragraph about granite cropping out as boulders in sandy soil matrix. That isn't a rock outcrop of granite, but rather a conglomerate with granite lithic fragments in it. That has little to nothing to do with the igneous processes involved... Although it may be worthwhile to discuss soils of granitic origin in terms of their sand and clay-mineral content. Snoop0x7b 00:32, 11 April 2007 (UTC)

Unpublished study

I corrected the false information on the E, H, & E report on granite countertops and inserted the actual results of the report documented with the section numbers where the information can be found. It is bad enough that an industry sponsored "study" is used in a factual discussion without it being quoted out of context.

Previous edits were reported as vandalism, likey by someone ignorant of the topic. I would hope that before that happens again, the person will take the time to read the actual E, H, & E report to verify the facts.```` —Preceding unsigned comment added by 70.245.25.31 (talk) 04:07, 9 May 2009 (UTC)

In the radioactivity section, someone posted information from the stone industries latest unpublished study, one that has been called "untrustworthy" by the chair of one of the two committees that the study was reviewed by (AARST).

I'm going to remove the information and post a copy here for disucssion.

I run an email group with many of the researchers looking into this subject, so I know a lot about the controversy. I also sit on the ASME committee looking into the controversy, and recently assisted AARST (Radon scientists) to organize a panel discussion on the controversy. The panel discussion still has to be approved by AARST officials, but it was initiated by them, and I have Dr. Steck, Dr. Kitto, Linda Kincaide (MPH, Industrial Hygienist, and certified Radon tester) and myself as the participents. I have also invited the MIA president, whom I know personally from the ASME work. Some of the senior AARST officals are calling for this panel discussion to center on the E,H,&E study and that the MIA president be disinvited and an official from E, H, & E be present to defend their work.

This is a product defense study, it has no place on a scholarly entry on Wikipedia.

Here is the removed section for discussion:

"A study of Granite Countertops by National Health and Engineering Inc of USA [3], undertaken in November, 2008 however, did not find a single granite that poses any health risk. Quantities of radon and radiation emitted by stones included in the analysis all fell well below average outdoor background levels that are commonly found in the United States. Scientists conducted more than 400 tests of 115 different varieties of granite countertops, including stones cited in media reports as being potentially problematic. The stones tested include types of granite that comprise approximately 80 percent of the annual U.S. market share for granite countertops, based on the most recent market data available."

—Preceding unsigned comment added by 70.233.179.200 (talk) 04:34, 15 February, 2009 (UTC)

I think the study as above, needs to be incorporated till such time as we have a definitive answer to the radioactivity issue for Granite. Any product has the right to defend itself against unproven propaganda, proven false by other studies. I am including the results of the study again.Kulveer (talk) 07:20, 16 February 2009 (UTC)Kulveer

Considering that the study is hosted by the trade organization and was likely financed by them, I do not see this as a reliable source. This would be like citing a study on smoking financed by R. J. Reynolds Tobacco Company on cigarettes, they had tons of studies that found the "health benefits" of cigarettes. We know the risks now, which is why a study that is hosted on the servers of the trade organization is very suspect. --Terrillja _talk 01:51, 5 March 2009 (UTC)

Exactly! Thanks for stepping up Terrillja. The study was paid for by the MIA, and they didn't even use calibrated instruments! I am doing some radon and radiation research, and my email group members insisted I use properly calibrated equipment, even loaning it to me if needed.

Here are some quotes from some of the experts reviewing this "study". The first sentence was lifted from a letter of complaint from the MIA to this author's editor, the balance is her response.

"Not one stone emitted radiation levels that were even close to the European Commission's negligible level for human health risk"

Ms. Currie’s statement is not in agreement with the MIA / EH&E report. From section 4.1.1.1 of that report:

Of the 39 stones tested, 18 had hazard index levels at or higher than 6, which corresponds to a dose criteria (sic) of 6 mSva-1.

According to the EC document Radiological Protection Principles concerning the Natural Radioactivity of Building Materials, building material with an Activity Concentration Index exceeding 6 should not be used in occupied structures. http://ec.europa.eu/energy/nuclear/radioprotection/publication/doc/112_en.pdf

A section of granite from my client’s kitchen had an Activity Concentration Index of 15.8."

End quote.

Here is an article from the same lady. It covers the Radon aspects of the "study".

http://greenbuildingelements.com/2009/02/20/granite-countertops-radon-what-the-granite-industry-doesn%E2%80%99t-want-you-to-know/

Here is a quote from a leading Radon researcher who is also an expert in radiation exposure. It was posted on a private email group, radon professionals, by Dr. Steck.

"As chair of the ad-hoc AARST group working on the radon-related aspects of this issue I feel that I must comment briefly on the statements of Mr. Loflin.

MIA publically released an Executive Summary of a report from their technical consultants in mid-November. Sometime later that month I received a copy of the full report but I do not think that report was widely circulated in the radon community. (Perhaps Mr. Loflin would share it with the list. ) After extensive critical examination, I have recently submitted an extensive set of questions to the MIA and their consultants about the contents of that final report to try to clarify their methods and results.

In mid-December, I received electronic copies of DRAFT proposals of pre-market and home screening protocols from MIA’s consultants. These documents came with the admonition that I was to keep them confidential even from the members of my committee. These documents were incomplete and did not contain scientific data that would be necessary to judge the effectiveness of the screening methods proposed. I have not shared these documents with anyone nor started a critical review of them in hopes that the final proposals would be more substantial.

Without going into lengthy technical detail at this point I would say that it is premature to expect even a tacit approval of the MIA’s proposed methodology or standards for radon-related risk assessment of indoor uses of decorative stone like granite."

End quote.

Here is another quote from a recent email from the same expert, Dr. Steck.

"-I do not believe that EHE or its subcontractor EMSL are calibrated in any fashion. That is one reason why I am skeptical of their results.

-The EHE report is confusing in reporting the number of measurements, materials tested, and results. I have been communicating with them and based on their responses here is what I believe to be the facts.

· The first measurements were made by a company called EMSL using (my guess no one has specified this in writing) small samples sealed in 5 gallon buckets with charcoal detectors for a few days. The average radon was “interpreted” to yield an emanation rate. I have seen a spreadsheet of the radon concentration results but no further description of method, QA or anything. All the samples 6”x6” x2 to 3 cm. They tested ~113 different types of stones, often multiple samples. They did measure Niagara Gold ,their #65, looks like 9 samples were done. I don’t know if the EHE report listed the mean, median or what for this material. I don’t think it matters because the EMSL data is untrustworthy and should be not be used to draw any conclusions.

· EHE measured full slabs ( ~5 or 6’ x 10-11’ wide) using a supplier different from the one that sent samples to EMSL. The EHE supplier says that Namibian Gold and Nile Gold are the same as Niagara Gold. I doubt if those slabs are still available nor do I believe that EHE is doing any more emanation measurements. EHE only measured 26 different types of granite."

End quote.

Incidently, they lied to Dr. Steck, Nambian gold, Nile Gold, and Niagara Gold are three different types of granite. They are trying to pull a fast one.

As the abstract for the September panel discussion on granite/radon/radiation was being submitted, AARST leadership asked that one of the authors of the E, H, & E study be present to defend their work. There is no doubt that the MIA has kicked a hornets nest with this "study". I expect that this study will be withdrawn before the September AARST convention.

Thanks for the back up on this, Terrillja. This MIA bunch are realy slimy and will stop at nothing to be able to contiue to sell radioactive stone to unwitting consumers.

Al Gerhart —Preceding unsigned comment added by Carpentershop (talk • contribs) 02:37, 5 March 2009 (UTC)

Radioactivity

This page has a high ranking in the google search so a lot of people are relying on this being accurate. One glaring error is the uranium content being so low, what was it, 10 to 20ppm? The richest veins of uranium in the world are at Rossing South Africa, contained in granite. Any thing over 80 ppm can be profitably mined at todays uranium prices, and some granite countertop materials contain far more than that. Here is a link to one granite countertop found in a consumers home, 270 ppm uranium, along with the other uranium decay products in equal amounts.

http://forum.solidsurfacealliance.org/viewtopic.php?f=7&t=79

There is even a court battle going on in Namibia, a uranium mine and a granite quarry fighting over the same land.

As to this being a wide spread belief, it is far more than that. Currently AARST (Radon scientists), CRCPD (state radiation office officials), and ASTM are all running committees on the problem. Even the EPA has taken the stance that while many granites are low level,say 5 pCi/G, there are lab reports showing up to 1,100 pCi/G in some commericialy sold granites.

One very important thing to remember is that "granite" sold as countertops is not your normal country rock. It can be basalts, pegmatites, schists, serpatines,just about any type of rock.

Take a look around on that site linked above, I run the thing, and I know just about every researcher in the country that is looking into this controversy. Matter of fact, I have provided the majority of the hot samples seen on the different TV stories out there. We ship samples out every month to researchers, some stationed at nuclear power plants. We have to ship it to their homes cause the samples wouldn't make it in the plant, too radioactive!

The uranium ppm in granite needs broken out into normal country rock and the exotics being sold as granite countertops. The later need to have upper limits of about 2,000 ppm, even as high as 50,000 ppm for hot spots.02:35, 23 November 2008 (UTC) —Preceding unsigned comment added by Carpentershop (talk • contribs)

Given the widespread belief that granite is a potential source of radiation, I think it would be appropriate to include something on the subject. In the UK, for example, radon (from, as I understand it, granite in the earth) is a big problem in some areas. I don't feel I know enough about this myself, but here's something I ferreted out which may be helpful:

Although all rocks and soil contain radioactive elements, the proportion they contain varies. Granite, for example, is high in radioactivity because it contains more uranium than most rock-types. The result is that some people in the country receive many times the amount of radiation as others, merely by living in, say, Cornwall rather than in Oxfordshire.

... Uranium decays eventually into a nonradioactive form of lead, but not before it has formed a long succession of intermediate radioactive elements. One of these is the radioactive gas radon. Radon is the biggest single source of natural background radiation. It accounts for almost half of our average annual radiation dose.

Average annual radiation dose in UK — 1300 µSv

Add 5000 (on average) if living in Cornwall

Add 300 if living in a well insulated house with low ventilation

Source: Radioactivity and Radiation, from the UKAEA. — Johan the Ghost _seance 15:43, 5 March 2006 (UTC)

In Australia, the aborigines avoid some granite plutons, and don't live on top of them. They say it's "sickness country". Oddly enough, these granites are some of the mosy highly radioactive in the world. Radon does come from granites, but not exclusively, as a lot of Proterozoic rocks can host weak roll-front uranium mineralisation, as can some forms of laterite, and some beach sands (those with high heavy mineral concentrations such as thorianite).

Is it worth putting a section into the granite page? Not really. It is more a function of soil than rock type; perhaps hunt round for an article on soil gas, basement or radon. For instance, while many people especially in tropical countries and warm climates live on granite, radon accumulation is only a problem in cold climates where house ventilation is restricted, or in areas where there are usually basements; the U.S. for example. In Australia, a huge proportion of the country areas are underlain by granite, but the climate is hot, favoring ventlated homes, and we don;'t have a penchant for basements.

If you want it, stick it in the see also section.Rolinator 23:33, 8 March 2006 (UTC)

Thanks for the info. I do feel that it would be worth a mention. You may be right in saying that it's more about soil than rock — I don't have much knowledge about that — but my point is that people are going to come here looking for the info, and we should help if we can, even if it's just to say "don't blame the granite, look in this other article". Given that the UK government is blaming the granite, as per the quote above, I think it would be worth discussing. — Johan the Ghost _seance 02:35, 9 March 2006 (UTC)

I don't have much knowledge about rocks, soil and radioactivity either - but does this mean that for example kitchen accessories or countertops made of granite are potentionally dangerous? Some of the best and most durable mortars and pestles (popular e.g. in Thailand) are made of granite. I was considering buying one, too, but this radioactivity thing has made me wonder whether food pounded in a granite mortar is "safe" or if it becomes "radioactive", too. I apologize if this is total nonsense...—J. M. 03:31, 21 June 2006 (UTC)

The amount of radioactivity released by a granite countertop is negligible, as is the amount o radon. To reiterate, the radon is only a problem in basements above weathered granites or in soils derived from granite, because the radon gets trapped in the soil, is heavier than air, and is collected within the basement. Your typical kitchen isn't a problem because it is regularly ventilated by windows and the fan in the rangehood(plus, it's only what, 50-100kg of rock?)

A granite mortar and pestle will contribute no measurable radioactivity to any food you grind in it. In fact, I'd say you would have more radioactive elements in the food than the granite bowl.

The average carrot, for instance, would have some potassium-bearing soil attached to its skin, same as a potato, etc. You can get rid of this is you peel it, if you are that concerned. Butpotassium is not a dangerous nucleide anyway, and you will get more exposure from walking out of your house all day to get your daily dose of radiation from the sun while exercising to stave off congestive heart failure.

The way I look it it is that the world is lethal to all life forms. You are going to be killed by something, or a combination of environmental things. This includes radiation. As an organism, you are successful if you get to breed and produce functional offspring before the environment or mishap or predation get you. As a human being, you may believe you can rationally limit the environmental damage received from radiation via any number of vectors, but that may be incidental to whether or not radiation is what kills you. Genetic damage from radiation, such as from UV, is entirely random, hence it is a risk, not a certainty, that cumulative exposure causes problems. There are guys running around who were working in the chernobyl reactor when it went critical, who are now 84 and in perfect health, so...stop worrying about the small things, and worry more about your heart and lung fitness and your driving, eating and sleeping habits or work stress levels. They'll kill you for sure; granite mortars and benchtops may, but no one could ever prove it. Rolinator 09:19, 21 June 2006 (UTC)

If you want to worry about radioactivity, don't worry about a carrot. Worry about your own body. The decay of a carbon-14 atom in DNA happens about 50 times per second, changing a carbon atom to one of nitrogen. (SEWilco 15:20, 21 September 2006 (UTC))

Check the tables that tell you how much radioactivity is okay. Check the radioactivity of the granite. If it's no hotter than vaseline glass, it's probably fine. The only other way granite is dangerous is in conjuction with gravity and inertia. Highly-radioactive granite does indeed exist. Just use common sense and check its radioactivity before using. Frotz (talk) 03:30, 10 July 2008 (UTC)

If you are afraid of radiation, don't get in a plane. Radiation from granite varies, but radiation form high altitude flying is known to be high. Either way, I added some things about how radon gets into houses, and how uranium gives off radon.--Terrillja (talk) 04:48, 19 October 2008 (UTC)

200 millirems per year

The text below has been moved to the talk page:

In buildings constructed primarily from natural granite, it is possible to be exposed to approximately 200 mrems per year. .

But 200 millirems is 200 * 1000 / 100 = 2 sieverts per year and 2 sieverts are "the typical background radiation from natural sources, including an average of 0.7 mSv/yr from radon in air". This is close to the minimum dose received by all humans anywhere on Earth" [4]. In other words, while this is true, granite does not add to this. I have removed this from the article as the text seems contradicting itself. Audriusa (talk) 19:21, 7 April 2008 (UTC)

NRC regulations require that any building or site be cleaned up to the point that the yearly dose be no more than 25 mrem per year. Using the testing protocol of the latest stone industry study, which calls for an exposure period of 4 hours per day, that allows any granite under 16 uR/hr, which is a really common radiation level for the more common granites. Some of the state radiation protection officials are saying it is insane to have to clean up a contaminated building if the next day a granite top can be installed that takes the building back to where it was before clean up.

Lots of talk about yearly doses but little understanding that those computed annual doses include a tiny fraction from building materials, and in this case, some granites will put out far more radiation than a person will get from all other sources. Almost all granites put out some radon to add to the yearly dose, but some granites will dwarf the exposure from a basement with a radon problem. 770 pCi/Sf/hr is the record radon emanation from granite so far, found by Dr. Kitto at NY State Health Dept radiological lab. Plenty of talk about carrots and human bodies, but neither will register on geiger counter or scintillator, straw man arguements at best.

I've seen 30 mrem/hr granite slabs for sale. I have tested granites that can fill a room with 30 pCi/L radon, which the EPA says is like smoking 3 3/4 packs a day.

And again, a plane at altitude will have around 30 uR/hr dose. I can link to some pictures and videos showing 500 and even 800 uR/hr. Given that most flights are less than three hours and the latest protocol states four hours exposure from a granite top every day, flying is not even close to the same risk from radiation.

"Just use common sense and check its radioactivity before using"

Exactly! If consumers don't know to test before purchase, common sense won't help them avoid the risks.

The final word on radiation must be the BEIR VII report which states there is no safe level of radiation, down to a single ionizing track through a single cell. They recomend avoiding as much as possible (ALARA) so using arguements of air travel, carrots, or minisclue potassium radiation has no bearing on the simple fact that an article about radiation in granite needs to point out that there are exotic varieties that are above source grade and are indeed dangerous.

Carpentershop (talk) 02:43, 13 March 2009 (UTC)

ORIGIN

Has anyone ever made granite?

Yes. No. Pick one depending on what you mean by that question. Rolinator 03:03, 19 May 2006 (UTC)

Does anyone here know what the hardness of granite is? On Mohs scale of Relative Hardness?

The mohs scale only applies to individual minerals. Not to rocks. But to answer your question, the minerals in typical grtanite are about 6.5 to 7 in hardness. In terms of rock strength the typical granite exceeds 700 Mpa strength. Rolinator

I believe the question refers to artificial granite to have ever been obtained from the composing minerals. A very interesting question. 79.116.232.188 (talk) 14:29, 13 August 2009 (UTC)

Chemical Composition

Is it in mol, in mass per cent or something else? 84.160.245.126 15:07, 19 November 2006 (UTC)

Good question, I've just checked the Lakeland Geology reference and it doesn't actually say. I suppose that this info is likely to be in one of the references given in the bibliography section of the book but I don't have easy access to any of them. JMiall 01:20, 20 November 2006 (UTC)

It was wt. % (technically mass percent), but I just replaced the data from a more recent source (1996 vs 1970 whatever) with the number of analyses listed for the average. Vsmith 02:44, 20 November 2006 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Granite/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

This article states that granite can be black. That is not the case as the classification of Granite defines it as having a colour index lest than 25. It cannot, therefore be darker than a light grey. Anything that is black is heading away from the chemical composition of ganite.

Last edited at 20:46, 21 June 2007 (UTC). Substituted at 08:08, 13 April 2016 (UTC)

alteration of granite

can anybody tell me what is the exact name of the product of alteration of granite, that is a sort of sand including minerals of granite. In french, it's called "arène granitique"

thanks for your help

jacques82.249.96.168 16:42, 31 May 2007 (UTC)

Perhaps you mean grus? No Wikipedia article at present; it is from German for grit or debris and is sometimes spelled gruss. It refers to the "decomposed granite" regolith, the coarse, angular fragments that are the product of (mostly) physical weathering of (usually) granite. Since it is created mostly by physical, not chemical weathering, grus is usually found in arid country. It is not absolutely always applied to granite; I have seen grus that derived from mechanically weathered gabbro. Hope this helps - cheers Geologyguy 18:47, 31 May 2007 (UTC)

Could it also be arenite?? Rolinator (talk) 12:19, 26 July 2008 (UTC)

thanks for your help. Is grus a commonly used word in english? "Arènes" apart from the "plaza de toros" meaning in french, is quite common in technical french, both geology and pedology/agriculture. It also applies to other rocks than granite, for example gneiss. In France, in Bretagne, Massif Central and Pyrenees, a large part of agricultural soils are grus. thanks again - jacques82.253.17.215 05:17, 1 June 2007 (UTC)

It's certainly common among geologists, and I've known a few non-specialists who use the word, but I would not say it is common in general use. In the US, at least, as mentioned, grus definitely applies to non-granitic rocks as well. Cheers Geologyguy 13:45, 1 June 2007 (UTC)

World´s longest tunnel above sea level through granite

Is the Lahdenvuori railway tunnel 4290 metres in Finland the longest tunnel through granite rock? Or is there longer one existing somewhere? This leaves out the Päijänne water tunnel, more than 120 kilometres, which is for sure the longest tunnel in bed rock made up mostly of granite. Just a question. —Preceding unsigned comment added by 88.113.116.245 (talk) 18:29, 24 July 2008 (UTC)

Problem with the "Modern Uses" section

It seems to me that the "Modern Uses" of Granite section needs to be greatly expanded. Granite is one of the most-important construction materials; used in building many skyscrapers, etc. and is actually one of the more important components of our modern society, when looked at from a certain point-of-view - - and yet the Modern Uses section is quite brief; it essentially just gives the subtopic short shrift in comparision with the other subtopics. i.m.o. it would be worthwhile to greatly expand this section - just for example, with a list of important buildings, skyscrapers, museums etc. where granite was used as an important construction material. There also, for example, is no description of how granite is currently mined, turned into "dimension stone," etc. and no mention of the industry behind all of this - dollar amounts per year, important mining corporations, methods of mining etc. —Preceding unsigned comment added by 69.127.200.152 (talk) 02:34, 18 June 2009 (UTC)

I'm uncertain whether this is an appropriate placement for my query, so my apologies in advance if it is not. I have heard that granite (in particular red granite) is a reasonable conductor of magnetic energy. I am interested to find out whether this is true and to what extent and why. Would anyone be able to provide more information with regard to this query, and if it is true, would it be possible to add it into the main page - perhaps under the Modern Uses section or a more relevant section please? Thanks! Merlyndraconius 18:16, 12 January 2010 (UTC) —Preceding unsigned comment added by Merlyndraconius (talk • contribs)

Polonium

One of the most toxic uranium decay products may be isotopes of polonium. In fact that may be behind much of the toxicity of the inert radioactive radon. I have asked granite quarriers, though, and they said that silicosis is a greater hazard in working granite than polonium or any other radionuclide. Did they not know of the above studies24.184.234.24 (talk) 03:21, 7 October 2009 (UTC)LeucineZipper

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.