Paul R. Potts
So, my latest eBay obsession is beautiful specimens of pure elements. There are some sellers that specialize in unusual collectible pieces such as spheres of pure zinc, cadmium, or highly polished silicon, ingots or cylinders of aluminum or tungsten, and balls or lumps of some of the more expensive metals like osmium and iridium, which are neck-and-neck for the honor of densest readily available element, and which have to be melted in strange and very expensive contraptions such as electron-beam furnaces.
Beryllium and lithium are reactive, and iridium and osmium are very expensive, so my second thought was that it might be fun to have some less expensive specimens the represent radically different atomic weights, such as equal-sized pieces of zinc and tungsten. If I can’t find equal-sized pieces, it would be cool to find similarly shaped pieces of the same mass, which would differ in size to a comical degree. I could also pick up an ingot if indium, which is an interesting, non-toxic metal that is extremely soft, and can be melted on a stovetop. I did not see any scandium, which is very expensive, or cesium or gallium, which will melt in your hand.
Tracking down a full set of attractive, pure specimens could very well be a full-time, and fascinating, hobby. A good place to start might be a set of attractive metals, like niobium and hafnium. But I probably should not try to take on yet another hobby, especially since I don’t have a nice spot to set up a display of these speciments. Sigh.
Besides the pure element specimens, eBay also has great mineral specimens, such as beautiful black tourmaline and fluourite crystals, which would go, presumably, on a different shelf. There are also some amazing fabricated specimens, like a silver-doped bismuth crystal geode that looks like a robot egg, and a piece of Gadolinium Gallium garnet with crystals of platinum embedded in it.
I had a great collection of display-quality mineral specimens when I was young, but someone it got lost or thrown out while I was in college, when my parents moved. I’ve always regretted that: there were some beautiful specimens, like big cubes of pyrite and some very nice amethyst crystals, a s well as various granites and volcanic obsidian.
Theodore Gray’s web site (theodoregray.com) has the fascinating details of his collection.