Thulium is a chemical element with the symbol Tm and atomic number 69.   It is the thirteenth and third-last element in the lanthanide series.  Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds;  however, the +2 oxidation state can also be stable.  In aqueous solution, like compounds of other late lanthanides, soluble thulium compounds form coordination complexes with nine water molecules.Thulium is the second-least abundant of the lanthanides, after radioactively unstable promethium which is only found in trace quantities on Earth.     It is an easily workable metal with a bright silvery-gray luster.  It is fairly soft and slowly tarnishes in air.  Despite its high price and rarity, thulium is used as the radiation source in portable X-ray devices, and in some solid-state lasers. ATT provides Thulium and compounds at a competitive price, including Thulium Acetate, Thulium Carbonate, Thulium Chloride, Thulium Fluoride, Thulium Metal, Thulium Nitrate, Thulium Oxalate, Thulium Oxide, Thulium Sulfate.