Cerium, which is the most abundant, ranks 28th, and thulium, the least abundant, ranks 63rd. Collectively, the rare earths rank as the 22nd most abundant "element" (at the 68th percentile mark). The non lanthanide rareearth elements, yttrium and scandium, are 29th and 44th, respectively, in their abundances.
Indium Indium's abundance in the continental crust is estimated to be approximately part per million. Trace amounts of indium occur in base metal sulfides—particularly chalcopyrite, sphalerite, and stannite—by ionic substitution. Indium is most commonly recovered from the zincsulfide ore mineral sphalerite.