Monazite powder

In geology, the mineral monazite is a reddish-brown phosphate containing rare earth metals and an important source of thorium, lanthanum, and cerium. It occurs usually in small isolated crystals. There are actually three different kinds of monazite, depending on relative elemental composition of the mineral: Monazite Thorium is a silvery radioactive, metallic element. ... Monazite Thorium is a silvery radioactive, metallic element. ... Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason)) is the science and study of the Earth, its composition, structure, physical properties, history, and the processes that shape it. ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ... In chemistry, a phosphate is a polyatomic ion or radical consisting of one phosphorus atom and four oxygen. ... A rare earth is an oxide of a rare earth element. ... General Name, Symbol, Number thorium, Th, 90 Chemical series transition metals Group, Period, Block ?, 7, f Appearance silvery white Atomic mass 232. ... General Name, Symbol, Number lanthanum, La, 57 Chemical series lanthanides Group, Period, Block 3, 6, f Appearance silvery white Atomic mass 138. ... General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 140. ... Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ...

• monazite-Ce (Ce, La, Pr, Nd, Th, Y)PO₄
• monazite-La (La, Ce, Nd, Pr)PO₄
• monazite-Nd (Nd, La, Ce, Pr)PO₄
• monazite-Pr (Pr, Nd, Ce, La)PO₂

The elements in parentheses are listed in the order in which they are in relative proportion within the mineral, so that lanthanum is the most common rare earth in monazite-La, and so forth. Silica, SiO₄, will be present in trace amounts, as will small amounts of uranium. The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery gray metallic Atomic mass 238. ...

Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in placer deposits. The deposits in India are particularly rich in monazite. It has a hardness of 5.0 - 5.5 and is relatively dense, about 4.6 to 5.7 g/cm³. An ore is a mineral deposit containing a metal or other valuable resource in economically viable concentrations. ... In geology, a placer deposit is a deposit of earth, sand, or gravel, containing valuable minerals in particles, especially by the side of a river, or in the bed of a mountain stream. ...

Because of the presence of thorium within monazite, it can be highly radioactive. If samples are kept, they should be placed away from minerals that can be damaged by radiation. Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ...

The name monazite comes from the Greek mona`zein (to be solitary), in allusion to its isolated crystals.

External links

• Monazite