Explanatory notes
… samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium). The heading … orange‑yellow prisms soluble in water) are used in photography as reducers. There are also double sulphates of … compounds of rare‑earth metals, e.g., xenotime (complex phosphates), gadolinite or ytterbite and cerite (complex …