A proportion used in determining the dimensional relationship of a representation to that which it represents: a world map with a scale of 1:4,560,000. b. A calibrated line, as on a map or an architectural plan, indicating such a proportion.
Yttria (yttrium oxide, Y 2 O 3), was discovered by Johann Gadolin in 1794 in a mineral called gadolinite from Ytterby. Ytterby is the site of a quarry in Sweden which contains many unusual minerals containing erbium, terbium, and ytterbium as well as yttrium.
Uses for Yttrium: ~Yttrium oxide is one of the most important compounds of yttrium and accounts for the largest use. It is widely used in making YVO4 europium, and Y2O3 europium phosphors to give the red color in color television tubes.ses for Yttrium: ~Yttrium oxide is one of the most important compounds of yttrium and accounts for the largest use. It is widely used in making YVO4 europium, and Y2O3 europium phosphors to give the red color in color television tubes.