In 1841 Mosander, having in 1839 discovered a new element lanthanum in the mineral cerite, isolated this element and also a hitherto unrecognized substance, didymia, from crude yttria, and two years later he announced the determination of two fresh constituents of the same earth, naming them erbia and terbia.
Of yttria, Y203, and 42.75 of the oxides of erbium, cerium, didymium, lanthanum, iron, beryllium, calcium, magnesium and sodium.
Yttria, Y203, is a yellowish white powder, which at high.
Solutions of yttria salts in their behaviour to reagents are not unlike those of zirconia.
By such a study in the ultra-violet region of a fraction prepared from crude yttria he detected a new element victorium, and subsequently by elaborate fractionation obtained the element itself.
The first earth of this group to be isolated (although in an impure form) was yttria, obtained by Gadolin in 1194 from the mineral gadolinite, which was named after its discoverer and investigator.
These crude earths, yttria and ceria, have supplied most if not all of the " rare earth " metals.
Yttria is an exceedingly complex mixture, which has been decomposed, yielding as an intermediate product terbia.