Discovered in 1907 by G. Urbain in Paris, France, and, independently, by C. James at the University of New Hampshire, USA. Lutetium is the hardest, densest and one of the rarest of the lanthanide group of elements (it has an abundance of 0.51 ppm in the earth's crust). It is found in some of the less common minerals (e.g. gadolinite and xenotime) and is difficult to isolate. Applications of lutetium tend to be limited to research only.Foil - Thin sheets of pure metal and metal alloys. Due to their fragile nature, some foils are coated on one side with an acrylic or polyester support. Where foils are supported they are indicated in the detailed item description.