Production: Although Helium is one of the most common elements in the universe it is a rare gas on earth. It exists in the atmosphere in such small quantities (less than five parts per million) that recovering it from the air is uneconomical. Helium is produced as a by-product of the refining of natural gas, which is carried out on a commercial scale in the USA and Poland. In these areas natural gas contains a relatively high concentration of Helium which has accumulated as a result of radioactive decay of heavy elements within the earth's c ....