HHomeBackground Color:He
LiBeIodine Pictures PageBlack White GrayBCNOFNe
NaMgIodine Technical DataAlSiPSClAr
KCaIodine Isotope DataScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr
RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe
CsBaLaCePrNdPmSmEuGdTbDyHoErTmYbLuHfTaWReOsIrPtAuHgTlPbBiPoAtRn
FrRaAcThPaUNpPuAmCmBkCfEsFmMdNoLrRfDbSgBhHsMtDsRgCnNhFlMcLvTsOg
Iodine     

Iodine

Atomic Weight 126.90447
Density 4.94 g/cm3
Melting Point 113.7 °C
Boiling Point 184.3 °C
Full technical data

Iodine sublimates into a beautiful violet vapor when heated: There's a torch under the plate in this photo. Iodine and iodine solutions were used as disinfectants before better antiseptic agents were found.

Scroll down to see examples of Iodine.
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!
Iodine Gastrografin

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Gastrografin.
A bottle of Gastrografin brand Diatrizoate Meglumine and Diatrisoate Sodium (lemon flavored). It is used sort of like barium sulfate solutions for doing x-ray imaging of the intestines.
Source: Anonymous
Contributor: Anonymous
Acquired: 13 January, 2010
Text Updated: 13 January, 2010
Price: Donated
Size: 3"
Purity: 37%
Iodine Opened iodine swab

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Opened iodine swab.
An iodine-alcohol swab, broken open to show the dark color of the iodine as it soaks into the cotton. The swab smells strongly of alcohol, but hardly at all of iodine.
Source: eBay seller survivorman2000
Contributor: Theodore Gray
Acquired: 22 April, 2009
Text Updated: 23 April, 2009
Price: $13
Size: 3"
Purity: <10%
Sample Group: Medical
Iodine Iohexol

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Iohexol.
And iodine-containing contrast agent used in imaging the heart in CT scans.
Source: Theodore Gray
Contributor: Theodore Gray
Acquired: 11 March, 2009
Text Updated: 12 March, 2009
Price: Donated
Size: 2"
Purity: <10%
Sample Group: Medical
Iodine Tincture of iodine,

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Tincture of iodine,.
Another bottle with tincture of iodine.
Source: eBay seller yougotitwebuyit
Contributor: Theodore Gray
Acquired: 1 December, 2008
Text Updated: 2 December, 2008
Price: $10
Size: 5"
Purity: 1%
Sample Group: Medical
Iodine Tincture of iodine, smaller bottle

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Tincture of iodine, smaller bottle.
And yet another small iodine bottle. I like this one, it's cute and the colors are nicer than the previous one, but the aspect ratio is not as good for a square photograph. Some day I will find the perfect iodine bottle.
Source: eBay seller cynlion
Contributor: Theodore Gray
Acquired: 6 April, 2007
Text Updated: 6 April, 2007
Price: $3
Size: 2.5"
Purity: 1%
Sample Group: Medical
Iodine Tincture of iodine, small bottle

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Tincture of iodine, small bottle.
Another bottle of iodine in alcohol, part of my search for the most beautiful medical iodine bottle for a poster project.
Source: eBay seller cynlion
Contributor: Theodore Gray
Acquired: 16 March, 2007
Text Updated: 19 March, 2007
Price: $3
Size: 2.5"
Purity: 1%
Sample Group: Medical
Iodine Tincture of iodine, large bottle

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Tincture of iodine, large bottle.
Iodine dissolved in alcohol is called tincture of iodine and was widely used as a disinfectant for cuts before the advent of things that don't sting as much.
Source: eBay seller pogodzinski
Contributor: Theodore Gray
Acquired: 16 March, 2007
Text Updated: 16 March, 2007
Price: $16
Size: 6"
Purity: 1%
Sample Group: Medical
Iodine Iodigum, iodine chewing gum

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Iodigum, iodine chewing gum.
$33 for a pack of gum? Well, it's an interesting antique pack of gum, I guess that's why it got bid up that high by gum collectors. (How do I know it was bid up by gum collectors, not element collectors? Because on eBay you can see who else bid on the item, and then you can look at what other items they have won recently. The other bidders on this item had bid mostly on old gum, gum advertisements, gum promotional items, and lady's handbags. No elements.)
I, of course, was bidding on it because of its elemental content, iodine, and I won. These days goiter, a painful and unsightly swelling of the thyroid glands in the neck, is virtually unknown in developed countries, because of iodized salt. Pretty much any normal salt you buy has a bit of iodine added to it, and a bit is all you need to prevent goiter. But before the deployment of iodized salt (why they picked salt I'm not sure), goiter could be a problem for people living in parts of the world where the soil was naturally low in iodine, meaning that their local vegetables, etc, didn't contain much iodine. This gum was sold for people to chew as a preventative: Today there would be no point because it's virtually impossible to not get enough iodine in a typical diet.
Source: eBay seller ddogmoxie
Contributor: Theodore Gray
Acquired: 20 January, 2007
Text Updated: 11 March, 2007
Price: $33
Size: 3"
Purity: 1%
Sample Group: Medical
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!
Iodine Plate of evaporating pellets

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Plate of evaporating pellets.

This is a photograph I took for my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Periodic Table Poster

I took this photograph because my other black-background iodine photos were not good enough to go with all the other black-background pictures in the poster. I wanted to capture the beautiful purple smoke you get when iodine is gently heated. (The iodine pictured here is of course gone now, having evaporated during photography.)

Interesting fact about iodine vapor: You can't photograph it against a black background. Absolutely cannot be done, period. Now, photographing smoke against a black background is easy: Just shine light in from the side and some of it will be reflected towards the lens, resulting in bright smoke against a dark background. (Some of the prettiest smoke ever is in this story I wrote about making a light bulb.)

But iodine vapor is not smoke. Smoke consists of millions of very fine solid particles, each of which absorbs some light, reflects some, and diffracts some. However, iodine vapor, while it looks for all the world like purple smoke, is in fact a gas consisting of individual molecules of iodine, which can only absorb light, not reflect or diffract it. So any light entering it will either be absorbed, or will continue on in the same direction. Shining light on it from any angle will not result in any going towards the lens, unless the light is shining directly from the back into the lens, which of course is another way of saying that the background is light, not dark.

Colored gases are extremely uncommon. In everyday life, any time you see air that does not appear perfectly clear, it's because there is a particulate smoke of some sort in it. (Fog, for example, is a smoke of water droplets.) You virtually never see colored vapor that isn't smoke, so even though I should theoretically have know it was impossible, I spent about half an hour trying to pour more and more light into the side of my iodine vapor to make it show up against a pitch black background. Only after I had several thousand watt-seconds of studio flash light concentrated on it did I suddenly realize the complete futility of the exercise.

So now you know why iodine is one of very few samples in my poster that are not photographed against a black background.

Source: Ian Brown
Contributor: Ian Brown
Acquired: 15 April, 2006
Text Updated: 29 January, 2009
Price: Donated
Size: 1"
Purity: 99.9%
Iodine Veterinary preparation

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Veterinary preparation.
Iodine is used as a disinfectant, or at least used to be. This vial contains 10 grams of resublimated iodine plus 3.5 grams of potassium iodide, and the label says it's from the "main veterinary place" in Berlin. It is said to be antique.
Source: Frank Liebscher
Contributor: Frank Liebscher
Acquired: 28 January, 2004
Text Updated: 11 March, 2007
Price: Donated
Size: 3"
Purity: 93%
Sample Group: Medical
Iodine Antique reagent bottle

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Antique reagent bottle.
I first suspected something was up with iodine when I noticed that some of the eBay auctions for it were anonymous, a sure sign that there was something edgy going on. It only took a few minutes of research to determine the reason: It's used in the synthesis of methamphetamine (crystal meth). Just as you can't go and buy a dozen large bottles of Sudafed anymore, you can't buy too much iodine without raising eyebrows and perhaps a posse.

It's not in any sense illegal to buy, own, or transport any amount of iodine, just like it's not illegal to go into Walmart and buy 10,000 Sudafed pills. But watch out if you do: tracking people who do is one of the main ways meth labs are found, at least that's the way it seems from the frequent newspaper articles saying so-and-so was arrested outside of Walmart with six bottles of pseudoephedrine. Maybe he just had a really bad cold?

Source: Anonymous
Contributor: Theodore Gray
Acquired: 8 May, 2003
Price: $40
Size: 4"
Purity: 99.9%
Iodine Antique iodine swabs

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Antique iodine swabs.
I don't really know for sure, but I strongly suspect these are iodine dissolved in alcohol, packaged in a single-use swab designed to be used in a first aid kit. Presumably you break the capsule releasing the iodine solution, then use it to disinfect a cut.
If you know better, please straighten me out.
Source: eBay seller suttonst
Contributor: Theodore Gray
Acquired: 3 May, 2003
Text Updated: 11 March, 2007
Price: $5.50
Size: 2"
Purity: <5%
Sample Group: Medical
Iodine Sample from the Everest Set

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Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.

To learn more about the set you can visit my page about element collecting for a general description and information about how to buy one, or you can see photographs of all the samples from the set displayed on my website in a periodic table layout or with bigger pictures in numerical order.

Source: Rob Accurso
Contributor: Rob Accurso
Acquired: 7 February, 2003
Text Updated: 29 January, 2009
Price: Donated
Size: 0.2"
Purity: >99%
Iodine Sample from the RGB Set

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Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.

To learn more about the set you can visit my page about element collecting for a general description or the company's website which includes many photographs and pricing details. I have two photographs of each sample from the set: One taken by me and one from the company. You can see photographs of all the samples displayed in a periodic table format: my pictures or their pictures. Or you can see both side-by-side with bigger pictures in numerical order.

The picture on the left was taken by me. Here is the company's version (there is some variation between sets, so the pictures sometimes show different variations of the samples):


Source: Max Whitby of RGB
Contributor: Max Whitby of RGB
Acquired: 25 January, 2003
Text Updated: 11 August, 2007
Price: Donated
Size: 0.2"
Purity: 99.9%
Iodine Small crystals,  99.99%

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Small crystals, 99.99%.
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion, and this one after I sent him some Mathematica t-shirts.

Click the story book icon for a story about contact explosives.

Source: David Franco
Contributor: David Franco
Acquired: 11 June, 2002
Price: Donated
Size: 0.05"
Purity: 99.99%
Iodine Tincture of Iodine I and NaI in water/alcohol mixture

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Tincture of Iodine (I and NaI in water/alcohol mixture).
Kindly contributed by Ed Pegg. William Kolb reports that the reason kids don't like iodine used as an antiseptic is not because iodine stings, but because the alcohol in which it is dissolved stings. How typical of the medical profession not to bother trying to find a better way to dissolve iodine, since alcohol is cheap and the only disadvantage is that it makes the patients scream. A bit of sodium iodide in the water is all it takes to allow iodine to dissolve without the need for alcohol, reports William's chemist friend.
Source: Walgreens Pharmacy
Contributor: Ed Pegg Jr
Acquired: 20 May, 2002
Text Updated: 11 March, 2007
Price: $5
Size: 3"
Purity: <5%
Sample Group: Medical
Iodine Terbium iodide.

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Terbium iodide.
Terbium iodide, very pure, but sadly not mine, just borrowed for photography.
Source: Anonymous
Contributor: Anonymous
Acquired: 17 April, 2009
Text Updated: 17 April, 2009
Price: None
Size: 0.25"
Composition: TbI3
Iodine Praseodymium iodide.

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Praseodymium iodide.
Praseodymium iodide, very pure, but sadly not mine, just borrowed for photography.
Source: Anonymous
Contributor: Anonymous
Acquired: 17 April, 2009
Text Updated: 17 April, 2009
Price: None
Size: 0.25"
Composition: PrI3
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!
Iodine Neodymium iodide

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Neodymium iodide.
Neodymium iodide, very pure, but sadly not mine, just borrowed for photography.
Source: Anonymous
Contributor: Anonymous
Acquired: 17 April, 2009
Text Updated: 17 April, 2009
Price: None
Size: 0.25"
Composition: NdI3
Iodine Manganese iodide

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Manganese iodide.
Manganese iodide, very pure, but sadly not mine, just borrowed for photography.
Source: Anonymous
Contributor: Anonymous
Acquired: 17 April, 2009
Text Updated: 17 April, 2009
Price: None
Size: 0.25"
Composition: MnI2
Iodine Erbium iodide

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Erbium iodide.
Erbium iodide, very pure, but sadly not mine, just borrowed for photography.
Source: Anonymous
Contributor: Anonymous
Acquired: 17 April, 2009
Text Updated: 17 April, 2009
Price: None
Size: 0.25"
Composition: ErI3
Iodine Cerium iodide

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Cerium iodide.
Cerium iodide, very pure, but sadly not mine, just borrowed for photography.
Source: Anonymous
Contributor: Anonymous
Acquired: 17 April, 2009
Text Updated: 17 April, 2009
Price: None
Size: 0.25"
Composition: CeI3
Iodine Iodargyrite

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Iodargyrite.
Sample of Iodargyrite (Ag I hex.), Broken Hill, Australia. Pseudo crystals, good little example. 0,7x0,6x0,5 cm; 1 g.
Source: Simone Citon
Contributor: John Gray
Acquired: 24 March, 2009
Text Updated: 25 March, 2009
Price: Trade
Size: 0.25"
Composition: AgI
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!
Iodine Photo Card Deck of the Elements

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Photo Card Deck of the Elements.
In late 2006 I published a photo periodic table and it's been selling well enough to encourage me to make new products. This one is a particularly neat one: A complete card deck of the elements with one big five-inch (12.7cm) square card for every element. If you like this site and all the pictures on it, you'll love this card deck. And of course if you're wondering what pays for all the pictures and the internet bandwidth to let you look at them, the answer is people buying my posters and cards decks. Hint hint.
Source: Theodore Gray
Contributor: Theodore Gray
Acquired: 19 November, 2008
Text Updated: 28 October, 2017
Price: $35
Size: 5"
Composition: HHeLiBeBCNOFNeNaMg AlSiPSClArKCaScTiVCrMn FeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAg CdInSnSbTeIXeCsBaLaCePr NdPmSmEuGdTbDyHoErTm YbLuHfTaWReOsIrPtAuHgTl PbBiPoAtRnFrRaAcThPaUNp PuAmCmBkCfEsFmMdNoLrRf DbSgBhHsMtDsRgCnNhFlMcLvTsOg
Iodine Iodargyrite from Jensan Set

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Iodargyrite from Jensan Set.
This sample represents iodine in the "The Grand Tour of the Periodic Table" mineral collection from Jensan Scientifics. Visit my page about element collecting for a general description, or see photographs of all the samples from the set in a periodic table layout or with bigger pictures in numerical order.
Source: Jensan Scientifics
Contributor: Theodore Gray
Acquired: 29 October, 2008
Text Updated: 29 October, 2008
Price: Anonymous
Size: 1"
Composition: AgI
Iodine Bromargyrite

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Bromargyrite.
Description from the source:
Bromargyrite var. Iodobromite ( Ag (I Br) cub.), Schoene Aussicht Mine, Dernbach, Germany. Little, definited yellow crystals on limonitic matrix. Very rare. 1,6x1x1 cm (crystals < 1 mm); 2 g.
Source: Simone Citon
Contributor: John Gray
Acquired: 30 September, 2008
Text Updated: 1 October, 2008
Price: Trade
Size: 0.04"
Composition: Ag(IBr)
The Elements book Mad Science book Periodic Table Poster  Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here!