Selenium is a non-metal element with the symbol Se and the atomic number 34 in the periodic table. It is chemically related to sulfur and tellurium, and rarely occurs in its elemental state in nature. The largest use of selenium world-wide is in glass and ceramic manufacturing, where it is used to give a red color to glasses, enamels and glazes. It is also used to decolorize the green tint in glass caused by iron impurities. It is used in as a human dietary supplement as well as in livestock. It is also used as an additive to enrich selenium poor soils, to improve the machinability of certain alloys. The declining electronic use has been in older copiers.