If you collect stamps, you toss them in an album. If you collect baseball cards, you toss them in a box. If you collect elements, well, you better think about where you're putting them.
"You have to start by studying chemistry, otherwise you're gonna get hurt," Theodore Gray, one of the world's foremost element collectors, told me. "I think that's an added bonus to any hobby."
Element collectors try their best to snag a sample of each of the 118 known elements that make up everything in the known universe. It's an impossible task, of course: Some elements, such as francium, decay into other elements almost instantaneously. Others have only been synthesized in a laboratory; a good handful are extremely dangerous or radioactive. Some are common, but are difficult to store. And that's half the fun.
A sample of pure sodium in its metallic state, for instance, can only be stored either in a vacuum, or in a tube that's been pumped full of one of those oh-so-noble gases (usually argon), which have the good sense to not react with anything.
"You take a thing like sodium and throw it into a lake, it explodes," Gray said. "What's important about the whole world of elements, what makes it so different from other hobbies, is that each one is interesting in its own way. Even if you find one that you think is pretty useless, you'll find some really specific use for it."
Gray would know. His book, The Elements, has sold more than a million copies and has come to be known as the bible of element collecting. The photos used in the book are all elements from his personal collection, which he keeps in his office. One of the best things about element collecting, at least in the old days, was sourcing the stuff.
"You can get almost anything on eBay now, but it didn't used to be that way," he said. "I spent years poking around places like scrap metal yards, talking to chemical companies."
And, while researching how to best score certain elements, you learn that, while it's generally illegal to buy neptunium, you can get a sample by buying a 30-year-old smoke detector that uses americium, which eventually decays into neptunium. You can get a polonium antistatic brush, used to clean LP records and film, but it'll decay into nothing within 10 years.
Today, the hobby is mainly dominated by sellers on eBay and a couple online shops, such as United Nuclear Scientific (which sells many scientific supplies in addition to pure elements), Metallium Inc., and Gallium Source.
"Our thing is to try and make this hobby available to individuals. We sell to NASA and MIT scientists and we sell to 12-year-old kids," Kurt Steinberg, who has run Gallium Source (it sells more than just gallium) for the last six years. "I have clients that specialize in different things. People want their elements to be beautiful, they want them to be interesting."
"If you look at something like bismuth, it's really boring looking. But then you look at the crystalline form, and it's fascinating. There's all these rainbow colors," he added.
Many companies sell element collector "starter kits." At Metallium, you can pay $695 for a set of 76 elements stored in tiny glass ampoules.
Or you can buy them piecemeal. At Gallium Source, you can pay $8 for a thin tungsten metal wire, or you can pay $250 for a rod of it. Sodium prices range from $111 to $1,000, depending on how it's stored and how much of it you're getting.
"The periodic table is a satisfying object because there's a slot for every single thing that exists or will exist"
There are element collectors who specialize solely in grabbing interesting specimens of a single element; grabbing all the noble gases (neon isn't the only one that looks good in sign form); collecting only precious metals; or crystalline versions of certain metals.
Others collect only radioactive or "dangerous" elements. It's not illegal to own almost any element (plutonium and certain types of enriched uranium excepted), but there are very strict shipping restrictions for radioactive and otherwise potentially dangerous elements.
But even though it's not illegal, you'll never own all the elements, because some of them are simply too unstable or difficult to procure—ununpentium, for instance, was discovered by physicists recently only after smashing particles together; hassium has a half life of a few seconds, so there isn't believed to be any on Earth right now. If you're going to be an element collector, you've got to be aware of those limitations
"There's a certain number of elements, and we're not constantly making more of them. If you're a stamp collector, you'll never own all the stamps," Gray said. "You'll never get everything, but you can come pretty darn close. The periodic table is a satisfying object because, that's it. It's complete. There's a slot for every single thing that exists or will exist. There's no holes or ambiguity, no question of whether it's finished or not. It's a scorecard."
This story is part of The Building Blocks of Everything, a series of science and technology stories on the theme of materials. Check out more here: http://motherboard.tv/building-blocks-of-everything