Rare metal is mainly used in the manufacture of special steels and super hard alloy and heat-resistant alloys, electrical industry, chemical industry, ceramic industry, nuclear and rocket technology, and so on.
Rare names have a certain degree of relativity, with the extensive research on rare metals, new sources and new extraction methods of discovery and expansion of the scope of their application, rare metals and other metal boundaries will fade, as some precious metal in the Earth's crust than copper, mercury, cadmium and other metals, and more.
Some rare metals on the physical-chemical properties and is not easy to separate into single metal. Past production and use very little, hence the name for the precious metals. 19th century that is rare (rare elements) term in the 1920 of the 20th century known as the precious metals on the basis of this. Rare developed relatively late, sometimes also called nu-metal (new metals). Since the second world war, due to the development of new technologies, demand increases, the precious metals research and applications development, emerging new metallurgical technology, production of these metals are also gradually increasing. Rare metals is not diluted. Precious metals including metal is also changing, such as Titanium is widely used in the modern technologies, production increase, so is sometimes included in the light metal.