|
|
www.mineralgallery.co.za Minerals K-O |
|
|
Monazite |
||
Name
Monazite
Chemistry
phosphate CePO4
Uses
a source of rare earths and Th.
Color
Monazite comes in a variety of colors such as brown, red, yellow, orange
Hardness
5 - 5.5 (brittle)
Specific gravity
4.6 - 5.5. Increasing with the thoria content.
Crystal system:
monoclinic, prismatic. Crystals are usually small and may be flattened (100) or elongated (010). Twinning on (100) common; sometimes cruciform.
Accompanied by:
rutile, zircon, ilmenite
Fracture
conchoidal to uneven
Luster
Resinous or waxy
Cleavage
perfect on (001)
Streak
grey-white
Similar to:
allanite
Monazite is a phosphate of the cerium minerals.
Test to determine if it is monazite
Monazite is insoluble in hydrochloric acid.
Infusible before the blowpipe.
When fused with sodium carbonate and the mass dissolved in nitric acid, ammonium molubdanate added to the solution produces a white to yellow precipitate indicating phosphate.
Distinguished from Zircon by crystal form and inferior hardness, and from sphene by form and specific gravity.
Occurences
Monazite is widely disseminated as an accessory mineral in granitic igneous rocks and metamorphic gneisses. Economic concentrations occur in beach sands. Ore grade concentrations in rock is rare.
Uses
Monazite is the principal source of thorium oxide(thoria), which is used in making incandescent mantles, and in refractories, chemicals and medicines. The rare earth metals and their salts are used in ceramics, tanning, dyeing and other industries.
Name
The name is derived from the Greek word for 'solitary', in allusion to its rare occurence in the first-known, localities.
