Thallium Element Cube

Thallium's atomic number is 81 and its symbol is Tl. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Discovered using flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek, thallós, meaning "green shoot" or "twig".  Commercially, thallium is produced not from potassium ores, but as a byproduct from refining of heavy-metal sulfide ores. Approximately 60–70% of thallium production is used in the electronics industry, and the remainder is used in the pharmaceutical industry and in glass manufacturing. It is also used in infrared detectors. This display is contained within crystal clear lucite acrylic.