Rare earths is a general term for the lanthanides and scandium and yttrium*** seventeen metallic elements in the periodic table. There are 250 rare earth ores in nature.

The earliest discovery of rare earths was made by the Finnish chemist John Gadolin, who isolated the first rare earth "element" (yttrium earth, or Y2O3) from a heavy ore shaped like pitch in 1794.

Because fewer rare-earth minerals were discovered in the 18th century, only a small amount of water-insoluble oxides could be chemically produced at that time, and it was customary to refer to such oxides as "earths" throughout history, hence the name rare earths. Extracted from the rare earth ore containing lanthanum, cerium, praseodymium, neodymium and a small amount of samarium, europium, gadolinium mixed oxides or chlorides by molten salt electrolysis to produce the metal. The total amount of rare earth is more than 98%, cerium is more than 48% of light rare earth. Easily oxidized to black in the air, can react with water at room temperature, and speed up when warmed up. It can be used as flint, alloy additives, and hydrogen storage materials.

A joint research team from Japan's Yamaguchi University, Ehime University and the University of Tokyo issued a communiqué saying they had discovered a new variety of minerals containing rare earths in Mie Prefecture. Rare earths play a role in transforming traditional industries and developing high-tech fields. The new mineral was discovered in April 2011 in the mountains of Ise City, Mie Prefecture, and is a special type of brown cordite containing the rare earth lanthanum and the rare metal vanadium, which was recognized as a new mineral by the International Mineralogical Association on March 1, 2013, and named "lanthanum-vanadium brown cordite".