Monatsiitti

Monatsiitti is a group of reddish-brown phosphate minerals that contains rare-earth elements, particularly lanthanum, cerium, neodymium, and thorium. The general chemical formula for monazite is typically represented as (Ce,La,Nd,Th)PO4, indicating that the rare-earth elements and thorium can substitute for each other within the crystal structure. Monazite is found in igneous rocks, particularly granites and pegmatites, and also in metamorphic rocks. It is often concentrated in placer deposits, which are formed by the weathering and erosion of its source rocks and subsequent deposition by water.

The economic significance of monazite lies primarily in its content of rare-earth elements, which are crucial components in many modern technologies. These include magnets, catalysts, phosphors for lighting and displays, and batteries. Thorium, also present in monazite, is a radioactive element that has been explored as a potential nuclear fuel. Due to its radioactivity, monazite can be a source of natural radiation and requires careful handling. The mining and processing of monazite are therefore subject to environmental and safety regulations. Major sources of monazite have historically been found in India, Brazil, Australia, and South Africa.