Discovered in 1901 by French chemist Eugene-Anatole Demarcay, europium was one of the last rare earth metals (lanthanides) ever discovered. Demarcay discovered europium while studying samarium an element which had been discovered only twenty years earlier. Europium as may be expected was named for the continent of Europe. Europium was the last element found in cerite after nearly one hundred years of research into cerites properties.
Europium is the rarest of the rare earth metals occurring in nature as is evidenced by it's concentration which is believed to be about one part per million. It's presence however is not limited to earth as light studies of the sun and stars indicate it is present in those bodies as well. Europium's most common ores are gadolinite, bastnasite, and monazite. Furthermore europium is the most chemically active of all lanthanides reacting quickly with water and oxygen in the air, so quickly in fact it can spontaneously combust which means it's handling requires great care. Incidentally europium does not occur naturally in the human body and it's ingestion is not suggested.
From a physical perspective europium is steel gray solid with a bright shiny surface and a density of 5.24 grams per cubic centimeter. It carries a melting point of 1,520 degrees Fahrenheit (826 degrees Celsius) and a boiling point of 2,712 degrees Fahrenheit (1,489 degrees Celsius). Europium is highly effective when it comes to absorbing neutrons which makes it valuable in regards to nuclear power production. Europium has two naturally occurring isotopes, europium-151 and europium-153. Europium further has a number of radioactive isotopes however none are currently useful commercially. Europium itself is extracted by heating with lanthum metal and costs anywhere from $1,400.00 to $2,000.00 per pound as only about four hundred tons are produced each year, primarily in the U.S., India, Australia, Brazil, China, and Sri Lanka.
Europium has sixty three electrons (with no charge), eighty nine neutrons (most common/stable nuclide), and sixty three protons. It has an electrochemical equivalent of 1.8899g/amp-hr as well as an atomic mass average of 151.965.
Europium compounds are most frequently used in making phosphors which are materials that shine when bombarded by electrons. In the case of europium phosphors a red light is created. Europium oxide which is produced by compounding europium metal and oxygen is sometimes used in making postage stamps which allows machine readers to distinguish the value of various denominations and as an anti-counterfeiting measure in European bank notes. When combined with yttrium it can be used to make red phosphors for televisions or fluorescent lamps as well as thin film superconductor alloys. When combining europium with yttrium first occurred in the 1960's it revolutionized the world of television as it provided vibrant reds for the first time that did not require the muting of other colors to keep a consistent scheme.
This is a quick overview of the element europium. While it is currently not a widely used commodity it may in the future see its demand rise as superconductors and nuclear power gain wider use and currency counterfeiting continues to be a rising problem.