A few years ago, I started to make my own element blocks with the goal of building the periodic table one block at a time. I know it will take some time and I will be missing samples for quite a few of them but I will spare no effort and continue to do so however long it takes.
I first sealed the samples in a glass ampoule and then proceeded to embed or encapsulate them in water clear resin (a polyester/styrene mix casting resin which becomes durable and strong once cured). An exothermic free radical polymerisation reaction occurs when the catalyst MEKP (Methyl Ethyl Ketone peroxide) is added to the unsaturated polyester/styrene mix resin reactant. During the curing process the polyester chains crosslink with each other to form a harder, more durable, thermo-setting polymer. After approx. 24 hours of curing the blocks look absolutely clear and impressive. The final touch is to engrave the name, symbol and atomic number of each element sample with the laser-cutter.
These are great to pass around and engage students without the risk of being accidentally dropped or broken. It makes a great addition to the science department at the school where I work and students have the chance to hold mercury (one of my favourites) for example, make observations, admire their beauty as the only liquid metal at room temperature safely without being exposed to its toxicity.
And in case there are any doubts regarding the Neon sample (it may be filled with air for all you know), below are two photos that show the effect of applying a high-voltage from a portable Tesla coil exciting the electrons of the atoms in the ampoule causing them to glow its characteristic red/orange colour.
Hope you enjoy this,