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Good article Osmium has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
June 18, 2009 Good article nominee Listed
WikiProject Elements (Rated GA-class, High-importance)
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Article changed over to new Wikipedia:WikiProject Elements format by maveric149. Elementbox converted 11:27, 14 July 2005 by Femto (previous revision was that of 22:25, 27 May 2005).

Information Sources[edit]

Some of the text in this entry was rewritten from Los Alamos National Laboratory - Osmium. Additional text was taken directly from USGS Osmium Statistics and Information, USGS Periodic Table - Osmium, from the Elements database 20001107 (via, Webster's Revised Unabridged Dictionary (1913) (via and WordNet (r) 1.7 (via Data for the table were obtained from the sources listed on the subject page and Wikipedia:WikiProject Elements but were reformatted and converted into SI units. Information in the main article concerning the infobox's value of Osmium's bulk modulus -- the value from a (controversial?) 2002 experimental result on osmium's compressibility -- was taken from journal articles by H Cynn et al in Phys. Rev. Lett. (original paper) and by B R Sahu et al in Phys. Rev. B (example of refutation), both of which are cited in full in the main article's References section.


Osmium 187[edit]

What is Osmium 187 used for?

why is isotopically pure 187-OS produced at all?

Is it just because pure 187-OS happens to occur in copper ore at Zhezkazgan / Kazakhzstan?

Why do interested parties pay 30,000 .. 60,000 USD (160,000?) per gram for isotopically pure 187-OS?

Best regards, Oscar

Osmium 187 can be used to increase the range and the power of atomic weaponry. AllStarZ 03:49, 13 February 2006 (UTC) says otherwise. points out that
If the precious metals actually had unique capabilities for enhancing the efficiency of fissile material, it might indeed be cost effective to employ them. No one is known to have actually used any of these materials as a fission tamper however. mentions:
Russian State Duma Security Committee member Viktor Ilyukhin (Communist) told Interfax on 11 Sep. 2002 that theKazakh copper monopoly Kazakhmys illegally producing osmium-187. Osmium-187 is not of any utility in nuclear weapons production and is more often used to gull people into paying excessive sums for radioactive material. There have been recent arrests of people in Moscow, St. Petersburg, and Volgograd wih samples of Osmium 187 in their possession..
Many many other hits via google on this subject. For all these reasons, I've removed the statement from the article. mdf 01:16, 10 March 2006 (UTC)

Os-187 is a naturally occurring isotope of osmium of 1.6% natural abundance. It is not radioactive. Os-187 is the only isotope of Os that has a spin 1/2 and therefore its compounds are suitable for study by nuclear magnetic resonance(NMR)spectroscopy. I was once offered pure Os-187 (i.e., 100%) and would have been interested in purchasing some but as you say it was too expensive. Drosmium Drosmium (talk) 01:15, 28 January 2009 (UTC)

Pictures of Osmium[edit]

I think we need a better picture of Osmium. The included photo doesn't do the metal justice. A picture that shows the beautiful blue cast of the metal would be nice.


Trust me, that stuff is extremely smelly, and toxic, so they often use it in an alloy if a large object requires its characteristics. AllStarZ 03:48, 13 February 2006 (UTC)

This is a beautiful image [1]

I have a beautiful sample of Osmium metal which I was able to capture in a photograph with the blue color. It has been uploaded and will soon be in this page. (Jdurg 00:39, 18 December 2006 (UTC))


why are the first few words of the precaution section in red, no other element's are? (

Remnant of on older style. Removed. Femto 13:08, 6 November 2005 (UTC)

Big Error[edit]

Osmium priices are grossly exaggerated! its price is abou $100/gram I'm correcting it accordingly

Resources: [2]


The price of Os(99.8%; 200 mesh) from Alfa ( 30/09): $99.8US for one gram, $397US for 5 grams. 22:17, 30 January 2009 (UTC)Drosmium

There is a big discrepancy between the prices quoted per gramme and per ounce. According to [4] the mid price today, 7 Oct 2010, is $380 per Troy Ounce, not far off the figure in the article, but this is about $12.20 per gramme, not $100. —Preceding unsigned comment added by (talk) 11:00, 7 October 2010 (UTC)


The price is as others said greately exaggerated (1000 times!!). Also, i am failing to see any resource that Turkey has the most resources in the world for Osmium. i am having a feeling that this information is injected here (price and location) for a scam. Please correct or erase this false information.

The reserves of Osmium in Turkey and Bulgaria are unveryfied. Where is the citation? According to, osmium and iridium are recovered primarily during the processing of Platinium and nickel ores. Thomas74 09:10, 29 September 2006 (UTC)

There are certainly big mistakes in evaluation of osmium sources. Osmium is one of the rearest elements. The main source of osmium is nickel-copper sulfide ores, which occur mainly in Canada, Cola and Taimyr Peninsulas (Russia), Australia ans South Africa. The Osmium assay in these ores only few ppb. The recovery of osmium is possible due to very high volatility of osmium tetroxide. Also together with other platinum metals osmium accompanies nickel until electrorefining operation, where osmium together with other PGM goes to the slime. Total production of osmium in the world is not more, than 50-60kg. Accordingly osmium reserve in the world is not more,than 1 metric ton. Osmium from nickel ores consists from six stable isotops (184,186,187,188,189,190). But some copper ores are enriched with rhenium, which exists as Re-187 radioactive isotope and slow transform in to Os-187 (Kazachstan). This osmium is recovered as pure isotope Os-187.

Densest Isotope: 192Os?[edit]

The article at present states:

If one distinguishes different isotopes, then the heaviest ordinary substance would be 192Os.

I haven't seen any source for this, and the mass number (A) for 192Os is 308, while the mass number for 193Ir is 309. (The two nuclei have the same number of neutrons — 116 — and differ in nucleon content only by a single extra proton in 193Ir. Admittedly, density does not vary directly with mass number, but the presence of an extra nucleon in one of two such otherwise very similar atoms should at least raise questions.) If there is a source for the claim that 192Os is the densest isotope, it should be given; otherwise, this claim should be removed.

Also, the term "ordinary substance" is vague, and should be made more precise. Is the article only excluding obviously non-terrestrial materials like the degenerate matter of neutron stars, or would it also exclude highly unstable radioactive isotopes?

Neuromath 20:34, 10 December 2006 (UTC)

Sorry, but you've got that wrong: The mass number A of 192Os is 192, and that of 193Ir is 193. Nevertheless, I also have strong doubts about Os being the densest "ordinary substance" (whatever that means), but Ir might well be less dense, because along with the added proton you also get an additional electron. And it is the combination of nuclear charge and electron configuration that determines the density (plus some other factors, such as crystal structure etc.). 14:02, 28 March 2007 (UTC)
I'd certainly expect Os-192 to be the densest elementary substance; the atomic masses of stable Os isotopes vary more than those of Ir, and already the average isotopic mixture of Os is more dense. Atomic mass is proportional to density only for isotopes of a single elements, otherwise uranium and plutonium would be much denser than osmium... --Roentgenium111 (talk) 13:29, 24 May 2012 (UTC)

Only High importance, not Top?[edit]

I'm quite surprised to see that this article's importance rating is only "High", not "Top". If "must-have for a print encyclopedia" is the criterion, I would think that any naturally occurring chemical element would rate "Top" without controversy. Would whoever assigned the "High" importance rating please explain their reasoning?

Neuromath 02:52, 11 December 2006 (UTC)

Color consistency[edit]

Osmium is referred to as being 4 different colors. In the lead, it is called blue gray and blue black. In the infobox, it is called silver blue. It is also referred to as blue white.

Wtf mate? ^^ --Cryptic C62 · Talk 01:42, 21 March 2007 (UTC)

Densest element or densest substance?[edit]

Apart from the Osmium/Iridium question, are these only the densest pure elements or also the densest substances (including compounds, mixtures and alloys) at normal Earth conditions? -- 12:39, 24 March 2007 (UTC)

The neutròn and other exotic "atoms", and individual particula are more dense. -lysdexia 15:38, 12 June 2007 (UTC)
Sure, but that's not what I meant. I was talking about substances at normal Earth conditions. If you want me to be more exact, let me add "substances that can exist for more than a tiny fraction of a second" and "substances of which you can have a block that's large enought to be visible to the naked eye." -- 17:29, 15 June 2007 (UTC)
I've been wondering the same thing. This article mentions that osmium can absorb hydrogen as an interstitial impurity, so I'm wondering if you could make osmium just that little bit more dense by doping it with hydrogen (preferably deuterium). I'm not sure about other possible interstitials, but carbon and boron might work. I don't know if anyone has tried studying such things yet. Stonemason89 (talk) 02:48, 31 July 2010 (UTC)
Density is traditionally quoted for purest materials of highest quality (no doping, interstitials, inclusions, voids, etc.), or it would be uncertain. Materialscientist (talk) 02:53, 31 July 2010 (UTC)
Of course, but that does not preclude one from measuring the density of such "impure" material, just to determine if it's more dense than pure osmium. (Some transactinide elements are predicted to have a density almost twice as high as osmium; they do exist for several seconds/minutes but visible amounts cannot be created, so they're excluded by the IP's 2nd condition.)--Roentgenium111 (talk) 13:21, 24 May 2012 (UTC)
This article claims that an Ir-Os alloy is slightly denser (22.7 g/ccm) than either of the two elements, but I don't know how reliable it is. --Roentgenium111 (talk) 22:15, 16 July 2012 (UTC)

Wrong word order?[edit]

From the article:

"As a strong oxidant, it cross-links lipids by fixing biological membranes in place."

Shouldn't this read: "As a strong oxidant, it fixes biological membranes in place by cross-linking lipids."

It seems that oxidant properties of the compound will result in the chemical change (the cross-linking of the lipids) which will then result in the physical change (fixed membranes). As the article reads now, the cross-linking occurs as a result of the immobilization of the membranes, which is misleading. Unless someone knowledgeable about the topic would like to correct me, I will fix this mistake. --Pyrochem 00:59, 28 April 2007 (UTC)

Just be BOLD. Femto 12:35, 28 April 2007 (UTC)

Osmium vs. iridium density[edit]

You can find a text on the subject from 1989 here. --Anshelm '77 13:40, 26 October 2007 (UTC)

That is quite interesting. So why don't you edit the osmium article to reflect this information and give the paper as citation?? Plantsurfer 16:22, 26 October 2007 (UTC)

Uses and Toxicity of Osmium[edit]

Uses of Osmium[edit]

- "Major uses for osmium tetroxide identified are for catalysis, especially in steroid synthesis, and for tissue staining." Osmium: An Appraisal of Environmental Exposure Environ Health Perspect. 1974 August; 8: 201–213.

- Nervous Tissue staining:

- caoutchouc staining:

The claim that "An alloy of 90% platinum and 10% osmium is used in surgical implants such as pacemakers and replacement of pulmonary valves" is incorrect. The following reference, Chevalier, Patrick. "Mineral Yearbook: Platinum Group Metals". Natural Resources Canada. Retrieved 2008-10-17. [dead link], is incorrect when it makes this claim; if you track down what this reference cites, you find that such alloys have been tested but there is no record of such alloys being used in actual implants.

Toxicity Osmium[edit]

the vapor of osmium tetroxide is extraordinarily toxic with MAC as low as 0.002 ppm.

- Procedure to neutralize Osmium Tetroxide with corn oil (corn oil is preffered because of its high percentage of unsaturated bonds) and Disposable nitrile gloves (NOT latex).

What is the toxicity of solid osmium. Can objects made of solid osmium be kept and handled safely? How easily does the surface oxidize? Does the metal need to be in powder form to create the dangerous osmium tetra oxide? Eric Thorsgard — Preceding unsigned comment added by (talk) 22:31, 10 July 2012 (UTC)

Turkey and Bulgaria[edit]

I will delete the wrong info, now! The USGS : World resources of PGM are estimated to be 100 million kilograms. U.S. resources are estimated to be 9 million kilograms. 100million kilograms are 100 kilo tons or 100,000 tons all the platin metals together. This artikle says :Turkey has 127,000 tons, of Osmium alone Osmium occurence is far less than 10% of Platinum. So I get ride of it.--Stone (talk) 11:44, 16 September 2008 (UTC)

The info was added 3 April 2006, which mkes it two and a half years.--Stone (talk) 11:53, 16 September 2008 (UTC)
While rare, Osmium does not necessarily bond with any other element, so it is possible for there to be such substantial Osmium reserves in turkey
No! No way that there is so much Osmium there in a mineable deposit. If there would be one, Turkey would be the lagest producer of Iridium Osmium and Platinum and somebody would have put it in a science journal a book or the internet.--Stone (talk) 20:56, 29 November 2008 (UTC)

B-class review[edit]

I wanted to ask if there is anything more I can do?--Stone (talk) 17:36, 17 October 2008 (UTC)

well, the Compounds section is still pitiful. Nice work though. Plantsurfer (talk) 18:23, 17 October 2008 (UTC)
Nergaal, you must be psychic! Plantsurfer (talk) 18:26, 17 October 2008 (UTC)

GA Review[edit]

This review is transcluded from Talk:Osmium/GA1. The edit link for this section can be used to add comments to the review.

This article deserves GA status. It is well written, neutral, stable and well referenced with in-line citations (thus verifiable). The topic is clearly of top importance. There were minor problems with style, references and a few statements, and some facts had to be added. All that was fixed in the review process. Other editors are encouraged to further improve this article. Some of the old comments comments are listed below. Materialscientist (talk) 09:36, 18 June 2009 (UTC)

1) Images are lacking. Suggestions: (i) Find a way to crop either File:Osmium 1.jpg or File:Osmium.jpg and put a cropped one into the elementbox. (ii) Remove File:Platinum nuggets.jpg as poorly related to this article. (iii) Find interesting images. For example, electron micrograph demonstrating advantage of Os staining (unfortunately, I haven't got my pictures on that). Materialscientist (talk) 09:55, 12 June 2009 (UTC)

wikicommons images on stained tem images might contain a image stained with Os, but i do not have a clue.--Stone (talk) 15:03, 12 June 2009 (UTC)
A colleague gave me a nice image on staining (which I put there), but this only partially solves the above image problem. Materialscientist (talk) 12:08, 13 June 2009 (UTC)
I think the Platinum nuggets are a good image for the article for the occurence section. Platinum placer deposits are the best place to find osmium iridium and most platinum nuggets contain osmium and iridium in a small amount.--Stone (talk) 11:37, 15 June 2009 (UTC)
Added another image of osmium.--Stone (talk) 20:58, 15 June 2009 (UTC)

2) "Osmium forms compounds with the oxidation states ranging from 0 to +8" conflicts with the elementbox values. Materialscientist (talk) 09:55, 12 June 2009 (UTC)

Have a look in Max Schmidt an Holemann.--Stone (talk) 15:03, 12 June 2009 (UTC)
DONE have ref for -2 and -1 and added it to the article.--Stone (talk) 11:37, 15 June 2009 (UTC)

3) Numbers 22562 ± 0.009 and 22587 ± 0.009 look wrong, and I would suggest converting into g/cm3.Materialscientist (talk) 09:55, 12 June 2009 (UTC)

good suggestion!--Stone (talk) 15:03, 12 June 2009 (UTC)
I already fixed that. Materialscientist (talk) 05:23, 18 June 2009 (UTC)

4) I didn't notice a reference for staining. Materialscientist (talk) 09:55, 12 June 2009 (UTC)

added ref for the staining.--Stone (talk) 15:03, 12 June 2009 (UTC)

5) Osmium easily oxidizes that should give it a tint. For example, is blue tint due to oxidation ? If so, please put it into the article.Materialscientist (talk) 09:55, 12 June 2009 (UTC)

The oxidation productis OsO4 from the ref, so I do not think this will cause the blue tint.-Stone (talk) 15:03, 12 June 2009 (UTC)

6) Numbers are needed on crust abundance, and preferably on distribution (meaning what is the major form, osmium-rich alloys like OsIr or osmium-poor, and which ones. I think the article only talks about major deposits, not major compounds). Materialscientist (talk) 12:08, 13 June 2009 (UTC)

:The two largest sources for PGMs are the low sulfide platinum ores and the sulfide copper nickel ores. Large deposits of the first type are found in south africa, while the second type is the main source for PGMs in Russia and Canada. After leaching of the copper nickel ores with sulfuric acid at elevated temperatures and elevated pressure under oxygen the residuals contain most of the PGMs which can be extracted with chlorine and hydrochlric acid. The dissolved PGMs are extracted by ion exchange extraction. The polymeric ion exchange resin can be burned and the residual ash contains most of the PGMs, which are separated from each other by clasical methods or chromatography. The two PGMs Osmium and Iridium are the compounds with the lowest concentration in the leaching residues. For example the concentrate 2 has a content of 450g/t of platinum while the concentration of Iridium is 37g/t and of osmium 26g/t.. doi:10.1595/147106704X1667.  Missing or empty |title= (help)

Added abundance for the continetal crust. 0.05ppb. This number is from 1995 and a good estimation, but most of the other numbers given in the Abundances of the elements (data page) are different and vary by two orders of magnitude. The numbers are not much better for iridium. so I took the newest and looked for others which are in the same order of magnitude.--Stone (talk) 07:25, 18 June 2009 (UTC)

7) Please search (I will too) applications of osmium coatings. I think they were used to increase UV reflection, but abandoned because of oxidation. Materialscientist (talk) 12:15, 13 June 2009 (UTC)

At 600A osmium has a reflectivity two times that of gold.. doi:10.1364/AO.24.002959.  Missing or empty |title= (help) UV spectrometers with osmium coated mirrors where flown in several missions also onboard the space shuttle, but it became clear that the atomic oxygen in low earth orbit is abundat enough to significantly deteriorate the osmium layer.. doi:10.1364/AO.24.002660.  Missing or empty |title= (help)
Added a few sentences on the topic with the refs.--Stone (talk) 20:47, 15 June 2009 (UTC)

A comment on the oxidation states. According to list of oxidation states of the elements, osmium can have not only all oxidation states from 0 to +8, but also oxidation state −2. --Itub (talk) 12:56, 12 June 2009 (UTC)

I don't really believe those lists because I found already several errors in other properties. Materialscientist (talk) 12:08, 13 June 2009 (UTC)
I believe in that list because I wrote it myself based on what I consider a reliable source and have double-checked every addition made by others. If you think there is an error, please let me know. --Itub (talk) 12:40, 13 June 2009 (UTC)
I respect that, but I have not found reliable evidence for Os 2- and 1- compounds yet. There is a mentioning that they correspond to osmium hydrogencarbonyls, but those are hard to find too. I'm am awaiting a comment from Stone on that. This might answer your question. I don't have access to the book you used in the list of oxidation states of the elements. If you could provide the primary source for Os 2-, this would be very much appreciated. Materialscientist (talk) 23:48, 13 June 2009 (UTC)
This is done and for both oxydation sates there is a ref.--Stone (talk) 11:37, 15 June 2009 (UTC)


Could one use this in tank armour? - Heaney555z (talk) 17:55, 26 February 2011 (UTC)

Only if you want osmium tetroxide slowly killing anyone inside the tank when someone spills their drink. Plus it would shatter, and cost too much. Basically, no. Scientific Alan 2(Click here to talk)(What have I done?) 22:12, 5 November 2013 (UTC)

Lanthanide contraction?[edit]

The article attributes osmium's density to the lanthanide contraction, but (1) osmium is not a lanthanide, and (2) the reference for that claim (n.4) nowhere mentions the lanthanide contraction.

Chemistry is not my bag, but it seems that this lanthanide bit is mistaken, or else needs some explaining. --Tbanderson (talk) 20:51, 22 March 2011 (UTC)

A book quote might help. --Stone (talk) 21:05, 22 March 2011 (UTC)
The fact that the lanthanide atoms decrease in ionic radius as atomic number increases means that Y and Lu have very similar ionic radii despite being one period apart, unlike Y and La (where La3+ is appreciably larger than Y3+). So the transition metal atoms in period 6 (including Os) are smaller than expected (they're about as large as their period 5 transition metal counterparts) but are heavier than their period 5 counterparts, and thus they're denser. Double sharp (talk) 05:34, 11 July 2012 (UTC)

File:Osmium crystals.jpg to appear as POTD soon[edit]

Hello! This is a note to let the editors of this article know that File:Osmium crystals.jpg will be appearing as picture of the day on September 27, 2011. You can view and edit the POTD blurb at Template:POTD/2011-09-27. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! howcheng {chat} 17:02, 23 September 2011 (UTC)

Picture of the day

Osmium, a member of the platinum group, is the densest naturally occurring element, normally found as an alloy, and also one of the least abundant. Very hard and with a high melting temperature, it is used in fountain pen tips, electrical contacts, and other applications where durability is required.

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