Explanatory notes
… cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium). The heading also covers … of rare‑earth metals, e.g., xenotime (complex phosphates), gadolinite or ytterbite and cerite (complex silicates) ( …