[8] Lutetium was independently discovered in 1907 by French scientist Georges Urbain, Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James.
[9] All of these researchers found lutetium as an impurity in the mineral ytterbia, which was previously thought to consist entirely of ytterbium and oxygen.
Lutetium usually occurs in association with the element yttrium[11] and is sometimes used in metal alloys and as a catalyst in various chemical reactions.
[21] Aqueous solutions of most lutetium salts are colorless and form white crystalline solids upon drying, with the common exception of the iodide, which is brown.
[24] Lutetium metal is known to react with the four lightest halogens to form trihalides; except the fluoride they are soluble in water.
[7] Lutetium, derived from the Latin Lutetia (Paris), was independently discovered in 1907 by French scientist Georges Urbain, Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James.
[27][28] They found it as an impurity in ytterbia, which was thought by Swiss chemist Jean Charles Galissard de Marignac to consist entirely of ytterbium.
[38] Charles James, who stayed out of the priority argument, worked on a much larger scale and possessed the largest supply of lutetium at the time.
[40] The main mining areas are China, United States, Brazil, India, Sri Lanka and Australia.
[41][42] Crushed minerals are treated with hot concentrated sulfuric acid to produce water-soluble sulfates of rare earths.
Several rare earth metals, including lutetium, are separated as a double salt with ammonium nitrate by crystallization.
[44] Lutetium aluminium garnet (Al5Lu3O12) has been proposed for use as a lens material in high refractive index immersion lithography.
[45] Additionally, a tiny amount of lutetium is added as a dopant to gadolinium gallium garnet, which was used in magnetic bubble memory devices.
[46] Cerium-doped lutetium oxyorthosilicate is currently the preferred compound for detectors in positron emission tomography (PET).
[49][50] Lutetium tantalate (LuTaO4) is the densest known stable white material (density 9.81 g/cm3)[51] and therefore is an ideal host for X-ray phosphors.
[55] The isotope 177Lu emits low-energy beta particles and gamma rays and has a half-life around 7 days, positive characteristics for commercial applications, especially in therapeutic nuclear medicine.
[43] The synthetic isotope lutetium-177 bound to octreotate (a somatostatin analogue), is used experimentally in targeted radionuclide therapy for neuroendocrine tumors.
[23] Similarly to the other rare-earth metals, lutetium has no known biological role, but it is found even in humans, concentrating in bones, and to a lesser extent in the liver and kidneys.