A sealed ampoule of pressurized supercritical liquid Carbon Dioxide embedded in acrylic.  Purity is 99%+.  This amazing sample will phase change before your eyes when heated to 35°C.  Let it cool down below 35°C and watch it condense back into the liquid phase again.  The front of the acrylic cube is the only side polished.  All others have some bubbles visible but the ampoule still displays well.  This is truly an amazing sample and fun to watch!  This fits perfectly inside the included 1 dram vial for display.