Talk:Diamond/Archive 5

My fellow wikipedians- Let me first say that I was a little hasty in labelling the sentence I edited weaselly, what I really meant was clunky and ambiguous. I only intended my edit to be a minor polish (really only the lightest of buffing), but seeing as it has created some slight friction, here is my rational: Why is this sentence not good?-

Some controversy over diamonds has been generated because of the monopolistic practices historically employed by De Beers including strict control of supply and alleged price manipulation, as well as the practice by some African paramilitary groups of selling conflict diamonds in order to fund their often violent activities.

1) This sentence is clunky. It is too long, and has a few ambiguities

2) The use of some is unnecessary (remove the some and the sentence says the same thing, only in a crisper fashion)

3) Controversy over diamonds -As in they do not really exist? They are bad for your health? Diamonds are really jellyfish? What the sentence actually means is that there has been criticism of the diamond industry.

4) The diamond industry is the subject of the sentence. The sentence reads better, and is less ambiguous if the subject (The diamond industry) is first. This is true for almost all complex sentences.

5) You only use the word alleged where there has been an unproven accusation- a proven allegation is no longer an allegation. DeBeers has been found guilty in the US of routine price fixing, and almost every independent investigation of the diamond industry agrees that DeBeers stiches up the market in one way or another. DeBeer's price fixing needs to be presented strongly, simply and as a fact, certainly not as an allegation.

6) The conflict diamond section is an area which is genuinely controversial in that the morality of supporting the various paramilitaries in Africa, is often unclear (are they goodies? are they baddies?). Some say the free market should not get involved in local politics. Some say it is unfair to single the diamond industry out for such practices. Therefore this is an area of controversy and not criticism, unlike supply restrictions and price fixing which are uncontroversial criticisms

7) Often violent activities is needless filler. If paramilitaries are violent then they are controversial, if they are nonviolent then they cease to be controversial to the point that people would protest against their involvement in commerce. Paramilitaries are sometimes violent, this is implied by the word paramilitary, so the reader does not need to be reminded that although they non-violently brush their teeth, repair schools, and drive cars, they also, on occasion, shoot people.

Therefore I find this version of the passage better for the reasons outlined above:

Weasel word
This really isn't my battle to defend but the difference in wording is within the Weasel word wiki policy. The policy was appropriately applied by naming who is causing the controversy instead of using a vague description of "some say". Supercoop 21:08, 20 September 2005 (UTC)
 * I've reviewed Weasel word and Avoid weasel terms and believe that the current usage does not merit a description as such. The sentence does not say "some say".  The sentence in question states unambiguously that there is controversy ("some" being a synonym for "moderate" -- neither fringe nor universal in awareness or acceptance; i.e. "some" quantifies the amount of controversy; it is not used to be vague about whether it exists or not) and states the reasons for controversy (#1, De Beers; #2, conflict diamonds).  The sentence accurately relates the facts as-known; De Beers definitely strictly controls supply, but price manipulation has only been alleged (i.e. they were accused of such in public media and in court), but not proven.  The replacement language is too heavy-handed in my opinion, and is a poorer depiction of the facts.  I'm not really sure if I've addressed the particulars you are concerned about, but thank you for replying on the talk page rather than reverting.  Hopefully we can work something out we will both be happy with.  - Bantman 21:41, 20 September 2005 (UTC)

'The diamond industry has been criticised for the monopolistic practices employed by De Beers who routinely control supply and manipulate price. The sale of conflict diamonds by African paramilitary groups has provoked controversy'

--Fergie 10:02, 21 September 2005 (UTC)


 * Thanks for your explanation. I agree that these things should be solved on the talk page, which is why I reverted in the first place -- I'm sure you didn't anticipate any disagreement making the change, but I wanted to talk about it first as it reads somewhat differently to me.  I see now that your edit improves the article, and appreciate your taking the time to show me why.  Thanks again. - Bantman 19:14, 21 September 2005 (UTC)

I agree that your edit produces a much better paragraph. As someone deeply troubled by conflict diamonds, however, I take slight exception to minimizing the brutality that those diamonds foster. Perhaps just one qualifying word or clause would retain the meaning that paramilitary groups are not merely "violent" but heinously so: "The sale of conflict diamonds by violent African paramilitary groups to fund has provoked controversy." "Paramilitary" does imply violence, but it does not convey even a small part of the violence associated with "blood" diamonds.

Units of mass
(Discussion moved to Wikipedia talk:Manual of Style (dates and numbers))

Reworking of Intro
Metaeducation made some edits to significantly pare down the intro; I reverted because it was a significant change that I happen disagree with. Let's discuss though, I promise I'm really not opposed to all changes!

The intro as it now stands tries to touch on each of the major divisions of the article. There are four paragraphs in the intro:
 * 1) Intro / etymology / chemistry / natural history / industry size
 * 2) Diamonds as gems
 * 3) Diamonds in industry
 * 4) The diamond production industry

I know the intro is long; in fact by convention we limit most intros to 3 paragraphs (I would argue here that paragraphs 2 and 3 are conceptually one paragraph, but split into two because of length). However, the article is also long, and I think it's important to touch on all the major topics covered by the article within the intro.

I think the intro serves both its purposes well: to introduce the remainder of the article, and to pique the interest of the reader. The intro also serves to highlight the most important aspects of the topic; the casual reader should be informed by the end of the intro that "diamond" as a topic has many more aspects than he or she might originally have thought.

I've leaned on WP:LEAD for my ideas on what a lead article should look like; let's try to reference our discussion to that, as I think it provides some useful guidelines.

All that said, it is a lengthy intro, and I would be happy to see it slimmed down if we can do so without dumping too much content or de-emphasizing subjects that should be called out. - Bantman 20:49, 18 October 2005 (UTC)


 * I was initially sufficiently bothered by the revert that I put mine back. Per my history comment, I don't accept blind revert back to a version that has two sentences in a row beginning "most diamonds are mined". thoughtfully study & integrate the good parts of changes or don't revert at all.  But I decided I was in a snippy mood in general today and reacting to knee-jerk action with something similarly bothersome.  So I went back to try and compromise while retaining what I think is obviously "better" writing layout, note new structure in line with the cited WP:LEAD article's 3-paragraph guideline:
 * Intro / chemistry / industry size
 * Applications of the diamond
 * Aspects of diamond production
 * (I'm starting to think that comments on the topic structure of each intro paragraph are necessary in the page source code, maybe we should keep them there instead of here.)
 * Though the lead should briefly summarize the most important points covered in an article in such a way that it could stand on its own as a concise version of the article, it's way too recursive for the first paragraph to summarize the introduction. Moreover, what to include should be evaluated for obvious tangents&mdash;where De Beers Headquarters are is one example, and considering they've got their own article anyway it's enough to allude to their industry dominance.
 * Talking through changes on this page is great, but the version history means well-intentioned editors aren't going to be able to make the article too bad for too long, good stuff can get migrated back in. I think be bold but deliberate and do the editing in parallel works better than reversion.  Best, Metaeducation 06:05, 19 October 2005 (UTC)

Gemological associations
Some supporting evidence for the claims about the relative integrity of the four gemological associations is required, else these comments should be removed. "(EGI) has a similar reputation to the IGL.", for example. A reputation viewed by whom? Does anyone hold a contrary view? --BillC 13:12, 30 October 2005 (UTC)


 * I think Bryan described the situation much more eloquently at Gemological Institute of America. While I wouldn't use it as a reference in itself, this PriceScope thread discusses the reputations of IGI and EGS, and although I can't vouch for the credentials of anyone posting there (and neither did I post there), I can say that (AFAIK) their conclusions are consistent with general consensus. I think it's fair to say that yes, in comparison to the GIA and AGS, IGI and EGL do have a reputation for less conservative grading practices. You'll note that the same sentence says that the IGI (and by the extension the EGL) are still generally respected; they've just got a certain reputation in the trade. There's nothing wrong with including this fact, IMO. It may seem unfair, but a diamond's retail value really can be affected by which laboratory issued its certificate&mdash;this is an unwritten "sixth C", if you will, after the "fifth C" of cost.


 * However, this section does go beyond mere reporting and seems to be leading the reader with its hypothetical scenario. The text in question appears to have been added by Barneygumble in mid September; perhaps he'll be by to give his own input. At present, I suggest removing the hypothetical scenario, and rewording the rest for greater neutrality. Another paragraph Barney added to the "Color" section is also problematic, as it seems to suggest nefariousness on behalf of IGI and jewellers in general: I'll remove this and add more detail on GIA's colour grading system. I'll also remove the unsourced images Barney added, as it's been 29 days since someone requested source info on his talk page, and their differing styles strongly suggest they were "borrowed" from several different commercial websites. Actually, a lot of what he added is already dealt with in the appropriate subarticles&mdash;while the information seems to be valid, I wonder if it's necessary to repeat it in the main article, given its already mammoth scope. Perhaps it should be redacted and relocated as necessary(?). Any thoughts on my comments and/or edits? -- Hadal 04:11, 31 October 2005 (UTC)


 * Good edits, Hadal. Kudos. I'm not a gemmologist, nor even a geologist, but the previous text twitched my POV-meter when I came by this article. --BillC 00:07, 3 November 2005 (UTC)


 * Thanks! Pointing out the problem was very helpful. Is it okay to remove the template? -- Hadal 04:13, 6 November 2005 (UTC)


 * I'll go ahead and remove the template (note timestamp). If you (or anyone else) have any further issues with the section, please let me know. -- Hadal 20:52, 19 November 2005 (UTC)

Refractive index
There's a little edit war going on over whether the refractive index should be given as 2.42 or 2.417 or whatever, but this article has a graph with respect to temperature that shows it as about 2.387 at 300K. If both of these are valid, that means we really only have two significant figures so it should be given as 2.4. Comments? —Keenan Pepper 18:13, 12 November 2005 (UTC)


 * What you propose sounds reasonable to me. It sounds to me diamonds come in a wide variety of purities and such, and that these factors, as well as environmental factors (as in the PDF that Keenan Pepper supplied) can affect the refractive index in the third significant digit. I am curious about the exact conditions under which User:T.E. Goodwin's sources measure the RI and what the exact properties of the gem are. It may be that the gemological measurement is simply different from the one used in semiconductor research and such. &mdash; HorsePunchKid &rarr;&#x9F9C; 21:41, 12 November 2005 (UTC)

Refractive Index is the ratio of speed of light in air divided by the speed of light in the substance. The R.I. of diamond is calculated where c=186,109 miles per second and the DECREASE in velocity after single refraction is 77,000 miles per second. Therefore, 186,109/77,000=2.417 This index is determined gemologically by utilization of monochromatic sodium light with a mean wavelegnth of 589.3 nanometers (5893 Angstrom). Gemologists universally accept the values of c=186,109 mps and decrease in velocity to 77,000 mps. You can expect them to vigorously adhere to the value of R.I=2.417 Apparently, the value cited as "about" or exactly 2.42 is determined by other means in semiconductor research, etc. I hope that this explains their adherence to the value of 2.417. Incidentally, T.E. Goodwin is a Graduate Gemologist of the GIA and has a background in gemological research. &mdash;The preceding unsigned comment was added by T.E. Goodwin (talk &bull; contribs) 2005-11-12 17:58:04.


 * Is that supposed to be the speed of light in vacuum, that 186,109 mi/s? If so, it is off, wrong, bad, almost one part per thousand low. Maybe it is in air; to be that precise, of course, you'd need a more precise description of the conditions than just "in air".
 * Does that 186,109 mi/s number come from multiplying 299,500 km/s times 0.6214 mi/km? If so, what is the metric value on which that 77,000 mi/s is based?  Or isn't it?
 * Even if you limit it to monochromatic 589.3 nm light, there's no way that diamonds with there various impurities, etc. will all be accurately described to four significant digits in the refractive index. Furthermore, that 77,000 mi/s figure doesn't necessarily have any more than two significant digits; using that, you cannot justify more than 2.4 for the refractive index.  Gene Nygaard 00:21, 13 November 2005 (UTC)


 * According to the article List of indices of refraction, the refractive index for air at STP for light with a wavelength of 589.3 nm is 1.0002926. That means that the speed of light in air at STP is 186,227.9 mi/s, unless I've miscalculated somewhere.  Pretty much throws that 186,109 mi/s out anyway; that would correspond to a r.i. = 1.00093.  Gene Nygaard 00:39, 13 November 2005 (UTC)


 * Of course, that same list of indices of refraction lists diamond at 2.419. Gene Nygaard 00:42, 13 November 2005 (UTC)

Speaking as an FGA, I'm really surprised to see anyone claim an RI of 2.417 is somehow incorrect. This constant, measured at 589.3 nm, is an accepted standard in both gemmology and mineralogy. Check any of the last 30 editions of the CRC Handbook of Chemistry and Physics, and you'll see they agree. Nobody's claiming that every single diamond has this precise RI; but diamond's constants are fairly constant, and deciding on a reasonably accurate third decimal makes it possible to calculate things like dispersion, theoretical cut angles (hi Jasper!), and other nifty things. Both 2.417 and "about 2.42" are correct in their own contexts, but if the wavelength is given, the former value is more accurate. For Gene's sake, here are some more precise numbers:


 * Velocity of light in vacuum: 186,282 mps
 * Velocity of light in diamond: 77,056 mps
 * Refractive index: 2.41748

So, because 4 is to the right of the last digit we want to retain (7), it's perfectly reasonable to quote 2.417. If you want to allow for (insignificant) variance, we could emulate webmineral.com's strategy, and quote 2.4175–2.4178. Frankly, I don't think this is necessary. -- Hadal 04:50, 13 November 2005 (UTC)

Diamond Glossary
I added a link to a diamond glossary. It was http://www.diamond-kontor.com/wp/diamond/diamond-glossary/ but it is removed. It is a informative glossary with a lot of terms concerning only diamond. Why is it removed?


 * Simple. Wikipedia is not a repository of everyone's favorite links. The site you linked to is a commercial site and not needed here. Please add content, not just links. Vsmith 12:03, 15 November 2005 (UTC)


 * What Vsmith said. You might also want to peruse Spam for more information. With your question above, you've essentially done as the link advises: suggest the link on the talk page first.


 * I can't support your link's inclusion for three reasons: it's inherently commercial; much of this information is already available within Wikipedia; and just skimming over the A–D entries has revealed several factual errors. For example, your explanation of dispersion disagrees with itself (it starts by defining brilliance), and ends with a falsehood: "Diamond has the highest dispersion (.044) of any natural, colorless gem." Diamond is actually noted for having an anomalously moderate dispersion in relation to its fairly high RI, and there are at least four natural, colourless to near colourless gemstones whose dispersions meet or exceed that of diamond (which is only rarely "colourless" itself). There are other errors, of course, but you're not paying me to fact-check. :) -- Hadal 03:28, 16 November 2005 (UTC)

Jewelery/Jewellery
I changed the spelling back to jewellery, because I am told by the New Oxford American Dictionary that the British spelling is jewellery and the American spelling is jewelry, and that neither place spells it jewelery. If this is indeed how it is spelled somewhere, someone please let me know where. In any case, we might as well be consistent with the jewellery article.


 * Sorry about that; just a mistake. I was more annoyed about the improper localisation of the word—so annoyed I failed to correct it correctly. Thanks for catching it, in any case! For what it's worth, it looks like this article is written in American English, so it's more important to be self-consistent than consistent with Jewellery. &mdash; HorsePunchKid &rarr;&#x9F9C; 2005-12-05 06:12:31Z


 * Oh, okay, that's reasonable. I didn't even bother to check what the rest of the article was like.

I love how pollite everyone is here. Its a plesant break from the rest of the internet. Sorry for being off topic, i just wanted to say that. --12.217.69.199 02:03, 27 January 2006 (UTC)

Anonymous Localization Attempt
I reverted the edits by 87.81.18.107 which changed the spelling of many words in the article toward the British spelling. It wouldn't be so bad if he/she had changed every instance of the terms 'jewelry' and 'jeweler' in one single edit, but many were missed in the five (!!) edits, leaving the article inconsistent. Please discuss such changes on the talk page first, and if you are going to make them, do a thorough job of it.

citation points to User:

 * Tolkowsky, Marcel (1919). Diamond Design: A Study of the Reflection and Refraction of Light in a Diamond. London: E. & F.N. Spon, Ltd. (Web edition as edited by Jasper Paulsen, Seattle, 2001.)

I took the User: ref out. Fplay 04:56, 12 December 2005 (UTC)

Toughness
Can anyone tell the exact toughness value for an average diamond?

Hardest diamonds
In case anyone wants to know, the diamonds from Copeton, New South Wales, Australia are the hardest. I could only find the following link online, though my professor did quote that the reason these diamonds were harder than other was their single-stage growth habit and not due to dislocations within the lattice. Either way, the 'gnaats certainly support my conception that these are the hardest stones within the known diamonds. That doesn't mean that you can't scratch other diamonds with less hard diamonds; i'm sure there is a continuum of hardness factors within the Moh's rating of '10'. And it doesn't mean that the softest diamond is a 9 and the copeton diamonds are a 10.5, or aanything silly like that. Cheers.

Trivia wise, the source of these diamonds has never been found (though a new diamond mine in Nimbin, NSW in marijuana country, has started, circa 2000. The Copeton diamonds are thought to have originated in an island chan offshore the Australian mainland which has been subsequently flooded or eroded.

Rolinator 10:17, 28 December 2005 (UTC)

Market Data
The market data for consumption, as well as production of diamonds appears to be wrong. Or at least the article is only quoting US numbers without stating that. I personally think that only stating US numbers is almost useless for an encyclopedic entry. The only important numbers would be world wide numbers. This can then be broken down to the biggest 5 producers and consumers to infer some kind of persepective. Producers could be broken down to gem quality<->industrial grit and artificial<->mined (so 4 groups) and consumption could be possibly broken down into various carat sizes, if that data is available. From http://www2.barchart.com/comfund/diamonds.asp it can be seen that mined production in 2001 was 68.5 million carat world wide, while industrial production was either 1.15 billion carat or 3 billion carat ( http://www.nsti.org/news/breaking.html?id=74 ). More input is needed to nail these numbers. --Dio1982 16:50, 23 January 2006 (UTC)


 * Without going back and checking, I think I recall the market data coming from De Beers-provided data and being confirmed by several other sources, referencing data for a more recent period than 2001 (which is the data provided in one of your sources). I agree that more effort into these numbers would be helpful, but as you noticed it is not easy to nail down a number as much of the actual production / consumption numbers are considered "secret".  In any case, the article indicates about 130 million carats mined and 400 million carats of synthetic diamonds produced annually, which (for mined diamonds at least) is significantly higher than the figure you cite, so I don't understand why you infer that it is referring to the US market only.  The monetary value is placed in US$, but I believe the figures represent the world market value. - Bantman 17:42, 23 January 2006 (UTC)

Something is definitely wrong $9bn/130m carats implies a carat on average has a value of less than $70...

3 Qwestions and a comment
Dear reader, I have a few comments and qwastens. I was wondering if a dimon could have any other structours besides a dimond structours, and if so what cind. Do you think that there could have been more dimonds on the earth befor man cind than now. How do dimons form? I know what the cimical make up is but I don't know how the gasses and qimicals come together to form such a butifull Mineral. I also wanted to know why dimons floress under a floressent light? Could it be that it's because all the different collors in a dimond come together and glow under a uv light. In the artical I read about dimonds it said that the only place there has ben a discovery of dimonds was Africa,Canada,Russia,Brazil, and aulstrailia but in different bookes I have read it said that there have beenfindings elswere.

By, Thesook Sathananthan


 * I agree with Johnathan, the sentence in the article does not read correctly.
 * (quote) Most natural diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, Russia, Brazil, and Australia.
 * The sentence is misleading when it reads like Indian diamonds did not exist at all.  I guess it meant to say "recent discovery".  From all the books that I read about diamond, they always said the ancient diamonds come from India before the African mines were discovered.  The indian diamonds were mentioned near the bottom in the section titled sources.  However, the sentence near the top probably needs some clarification.
 * Kowloonese 08:32, 7 February 2006 (UTC)

By:Thesook Sathananthan

Jupiter Diamond?
According to the article on 2061: Odyssey Three, "an article in Nature magazine in 1981 hypothesising that the core of Jupiter was in fact a diamond the size of Earth, caused by the compression of carbon." Is this still believed to be a possibility? Should it be mentioned in the diamond article? - Comment by Jon the Geek, 23:31, 10 April 2006


 * Nobody really knows for sure, but these days the romantic "diamond core" is usually speculated with respect to white dwarfs exclusively. The carbon left over after a star dies is of much higher purity than that found in gas giants, leading people to think a diamond core is more likely to be found in dead stars. The popular press tends to give this speculation more attention than it perhaps deserves; I don't think it deserves any attention in this article, either. Galileo revealed Jupiter to contain unexpectedly low levels of water, and an enrichment of carbon. One new hypothesis regarding the formation and composition of Jupiter's core suggests it is a ball of tar laced with rocky bits, enveloped by a layer of liquid metallic hydrogen. There may not be any solid material at all. -- Hadal 04:54, 13 April 2006 (UTC)

4 types of diamonds (1a, 1b, 2a, and 2b)
types of diamonds

According to this link, natural diamonds can be categorized into 4 types... Diamonds can be scientifically classified into 4 types, known as type 1a, 1b, 2a, and 2b.

I added this link to the "External Links" section, but if these type categorizations, are correct, I would like to suggest that this information be added in a more prominent part of the Diamond entry. Any comments about this?

Amount
"DIAMOND" has been mentioned 561 times in the article.

- lol thats alot, i hope you didnt count them. i saw an artical somewhere and every 3rd word was... well i cant remeber but it was strange 0_o Gludatizblu 10:27, 24 August 2006 (UTC)

Crater of Diamonds
Could someone add information regarding the Crater of Diamonds State Park in Murfreesboro, Arkansas? --Eddylyons 01:39, 12 June 2006 (UTC)

Hardest metal known the man
This hardest metal BS is a joke from 4chan. Some moron on GameFaqs was trying to sound smarter than he actually was and declaimed that "diamond is the hardest metal, if not THE hardest metal, known the man." No typos there. That's actually what he said. So, yeah, it's not somebody genuinely being misinformed, it's vandalism. And if a 4channer sees this and tries to delete it, I've got it copy-pasta'd. Don't waste your time.

Controversy about diamond market
Shouldn't there be some discussion at least of articles like http://www.edwardjayepstein.com/diamond/chap13.htm (about the cynical 1940s campaigns to entrench a link between diamonds and "romance") and http://www.fguide.org/Bulletin/conflictdiamonds.htm (regarding the controversial way the diamond industry operates)?Mrlefty 01:11, 1 July 2006 (UTC)

Added something from History Channel Special
As I watch the History Channel's modern marvels story on diamonds, they mentioned that diamonds have grains like wood does. I have added this to the cutting (shaping?) section of the article.--Ben414 00:04, 25 July 2006 (UTC)

Nyf, either a hoax, or needs citation and explanation
"Diamonds (especially those from secondary deposits) are commonly found coated in nyf, an opaque gum-like skin." - This really needs expanded on, or cited, as it sounds, literaly, incredible. If this nyf substance exsists, we need explanations (Whats it made of?) and photos if possible. There is no other direct confirmation of this on the www that I can find. --AudioPervert 14:25, 28 July 2006 (UTC)


 * I've provided a citation from one of the most reputable texts on gemstones; although it does not go into any further detail than what I've related here, nyf is surely not a hoax. The term belongs to the argot of diamond miners and dealers, who don't seldom share their knowledge with outsiders—hence the obscurity. I regret that I can provide neither images nor elaboration. I could speculate about nyf's composition (diamond is strongly lipophilic, so perhaps it's some sort of naturally accumulated hydrocarbon) but that wouldn't be very encyclopedic. If I find any further information, I'll make a point of including it here. —Hadal 19:49, 19 August 2006 (UTC)

♦ ; %E2%99%A6 ; [%E2%99%A6] ; ◊ ; %E2%97%8A ; [%E2%97%8A] :
It does seem as though someone's made a booboo.

Where is the "shape" symbol article?

Hopiakuta 18:11, 19 August 2006 (UTC)

♠ ♥ ♦ ♣
♠ ♥ ♦ ♣.

Hopiakuta 18:23, 19 August 2006 (UTC)

Kohinoor not mentioned
A FA on Diamond and the Kohinoor doesn't even get a passing reference. I could add it but I'm not an expert on this subject and I don't wish to plug it in somewhere just for the sake of it. But editors involved could atleast link it in the right place. --Idleguy 18:28, 5 September 2006 (UTC)

X-ray fluorescence?
Seems something here needs clarification:
 * Nearly all diamonds fluoresce bluish-white, yellow, or green under shorter X-ray radiation. X-ray fluorescence is used extensively in mining to separate the diamond-bearing from the non-fluorescing waste rock.

X-ray fluorescence is an analytical technique - and this seems to imply large scale x-ray radiation to produce visible fluorescence of diamond bearing rock. Changed to X-ray screening, but need a citation or further clarification. Vsmith 00:00, 18 September 2006 (UTC)