Pondering how to go about it best, but theres one particular large, well-formed chunk of I2 in my order that would be ideal for display purposes in an element collection (iodine, obviously, THIS festering den of iniquity is not going up on my lab wall haha), its volatile of course, so sealing it in a glass ampoule under argon would be the obvious, but, I'd sooner it retained its original form if I do. Never actually seen it before take the form of solid rounded but pitted boulders like this stuff came in. I usually buy it in flakes, and if I make it from iodides then its sublimed to purify it, and takes the form of..well..fluffy looking tiny crystals. I can only think of a built in coolant system using a computer fan, and something similar for storing other unstable or volatile elements, such as white tin, and the yellow allotrope of arsenic (analogous to white phosphorus), as well as the odd, and possibly unstorable explosive antimony, an strange allotrope of antimony prepared via electrolysis of antimony trichloride at antimony electrodes, or something similar, forget the exact route, but it detonates when subjected to friction.
Been wanting to go the whole hog so to speak and build a really nice looking periodic table-layout case, everything from hydrogen to maybe, neptunium. (via neutron bombardment of a very thin layer of depleted uranium to transmute it through 239Pu and thence to neptunium. Or perhaps a higher cutoff, whenever stability becomes too poor for stable safely storable isotopes. Thinking first targets will be the semimetals, as they lie roughly in the middle, saving IMO polonium for the last of them, then technetium for the last of the transitions. Although polonium samples aren't too hard to obtain. (insert russian spy gallows humor here)
Iodine and sulfur can start of course, as these are already sitting on the shelf, then Cl2, as that I can knock a sample of up, dry it and seal it in a gas discharge tube in no time. Been eyeing up some rather attractively priced rhenium and iridium too, $20-something a gram, powder, meaning I can save most of both for precious metal catalysts:D Can already sort platinum, silver and palladium, the former two as the metals and palladium through reduction of palladium dichloride.
Phosphorus I think will be next, as there are so many different forms of the element to nail down. Black phosphorus (both of them) IMO will be hard, if even possible, those I MAY have to buy. Since the synthesis from white phosphorus requires both intense heat and great pressure.
IF its possible to store, one thing I plan to try is to clean the oxide surface layer off willy pete with a chromic acid/concentrated sulfuric bath, which when melted and stirred under the strongly oxidizing cleansing bath, will burn up the P2O5 layer that gives it the usual white color. Seen a pic just after someone did it, and he got it damn near clear as glass. But UV tends to cause rewhitening. Thinking clean it, dry it, then ampoule under dry inert gas, in a tube of some kind of glass that blocks UV even more effectively than soda-lime glass, to see if it can be stored clear, prevented from reoxidizing. Got a little P to start with, so I don't have to build a plasma arc furnace and do a nasty messy carbothermic reduction and get P2O5 smoke everythehellwhere. Because if theres one thing phossy does well its SMOKE like crazy when ignited.