Of the rare earths Lanthanum proves to be one of the easier metals to find - if you don't mind owning a cloudy oxidized piece swimming in oil, that is. The metal is normally shipped in canisters filled with mineral oil. The mineral oil is a good preservative but a thin layer on top of the metal spalls off as whitish lanthanum oxide and leaves behind a more stable form of the oxide that prevents the metal underneath from further corrosion. While irrelevant in terms of its use in the laboratory it's not very aesthetically pleasing. To get shiny lanthanum, small pieces are taken straight from the distillation chamber and placed in an inert atmosphere which fully prevents any oxidation. The samples we sell are stored in argon, in ampoules which are then encased in a 2x2 inch (50x50mm) block of crystal clear Lucite acrylic.