Cerium

Description: Cerium is a lustrous, malleable and iron-gray metal. It oxidizes quickly at room temperature, especially in moist air. Except for europium，Cerium is the most reactive rare-earth metal. It decomposes slowly in cold water and quickly in hot water.

Source: Cerium is the most abundant rare-earth metals. It can be found in minerals such as allanite (also known as orthite), monazite, bastnasite, cerite, and samarskite.
Metallic cerium is produced through metallothermic reduction techniques such as reducing cerous fluoride with calcium, electrolysis of molten cerous chloride, and other methods. The metallothermic method yields high-purity cerium.