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Barium getters. When you need a really good vacuum, and you need it to last a long time, the concept of "air tight" takes on a whole new meaning. For example, glass leaks. Not the seals or joints, but the glass itself. Radio tubes, discharge lamps, and similar applications require a level of perfection in their vacuum and/or inert gas atmospheres that cannot be achieved by any practical container: No matter what you make it out of, it's going to leak too much. The solution is to place inside the sealed chamber a substance, known as a "getter" that absorbs stray traces of moisture, oxygen, or other undesirable contamination that works its way through the glass or metal. Since only a small amount of impurity is going to work its way through, a small amount of getter can keep the system clear for the lifetime of the product. (The getter also clears out any contamination you may have introduced at the beginning, making manufacturing perfection less important.) Barium is a common getter, and this barium getter wire was manufactured in 1941 for use in radio tubes, and has remained sealed in an unopened vacuum can ever since. My theory is that it's because the opening key (not visible in the photos) apparently broke off when someone tried to open it (there is a residual stem where it was attached to the lid). I guess one thing we can be sure of is that the vacuum in that can is really, really clean. Source: Ethan Currens Contributor: Ethan Currens Acquired: 30 October, 2006 Price: Donated Size: 2" Purity: 99% |
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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 gasses) 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 Price: Donated Size: 0.2" Purity: >99% |
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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 Price: Donated Size: 0.2" Purity: 99.5% |
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Rough octahedra under oil. I'm not sure what process resulted in these shapes: They look sort of crystal-like in overall shape, but the surface looks more mechanically-formed than crystalline. As an alkali earth, barium is reactive enough that it must be kept under oil to prevent rapid deterioration into barium oxide. I chose this sample to represent its element in 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.  Source: David Franco Contributor: Ed Pegg Jr Acquired: 16 August, 2002 Price: $23 Size: 0.3" Purity: 99.5% |
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Baryte. Description from the source: Baryte (Ba SO4 orth.), Julcani Mine, Huancavelica, Peru. Tabular crystal cluster. 3,5x3,5x2 cm; 22 g. Source: Simone Citon Contributor: John Gray Acquired: 30 September, 2008 Price: Trade Size: 1.4" Composition: BaSO4 |
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Baryte. Description from the source: Baryte (Ba SO4 orth.), Miraflores Mine, Huanuco, Peru. Small but gem crystals, very nice. 0,8x0,8x0,2 cm; 10 g with box. Source: Simone Citon Contributor: John Gray Acquired: 30 September, 2008 Price: Trade Size: 0.3" Composition: BaSO4 |
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Barite. The tag that came with sample reads as follows: Barite - BaSO4, from Sandoval Co., NM.I traded this sample for a few of my strange copper nodules. Source: Calvin Webb Contributor: Calvin Webb Acquired: 1 September, 2003 Price: Donated Size: 1" Composition: BaSO4 |
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Romanechite from Jensan Set. This sample represents manganese 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: Jensan Scientifics Acquired: 17 March, 2003 Price: Donated Size: 1" Composition: (Ba,H2O)2Mn5O10 |
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