Monazite
Brazil
0.16 carats
© Brian Kosnar - Mineral Classics
Monazite forms tabular or prismatic crystals of yellow, yellow-brown, brown, rose-red, reddish-brown colour. Colour change from reddish orange in daylight to pinkish brown in tungsten light has been reported.
Monazite usually contains small amounts of Th or sometimes U, both making it radioactive.
| General Information | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Formula |
| |||||||||||||
| Physical Properties of Monazite | ||||||||||||||
| Mohs Hardness | 5 to 5.5, Gemmological Tables (2004) More from other references | |||||||||||||
| Specific Gravity | 4.80 to 5.50, Gemmological Tables (2004) More from other references | |||||||||||||
| Cleavage Quality | Perfect, Gemmological Tables (2004) | |||||||||||||
| Optical Properties of Monazite | ||||||||||||||
| Refractive Index | 1.796 to 1.841, Gemmological Tables (2004) More from other references | |||||||||||||
| Optical Character | Biaxial/+, Gemmological Tables (2004) More from other references | |||||||||||||
| Birefringence | 0.045, Gemmological Tables (2004) More from other references | |||||||||||||
| Colour | ||||||||||||||
| Colour (General) | Yellow, yellow-brown, brown, Gemmological Tables (2004) Colour change: reddish-orange/greenishMore from other references | |||||||||||||
| Colour (Daylight) | Colour change (reddish orange in daylight to pinkish brown in tungsten light) is reported but is common enough when RE are involved in the composition., Gems, Sixth Edition (2006) | |||||||||||||
| Colour (Incandescent Light) | Colour change (reddish orange in daylight to pinkish brown in tungsten light) is reported but is common enough when RE are involved in the composition., Gems, Sixth Edition (2006) | |||||||||||||
| Transparency | Transparent, Gemmological Tables (2004) More from other references | |||||||||||||
| Fluorescence & other light emissions | ||||||||||||||
| Fluorescence (Long-Wave UV) | Some specimens have shown a greenish fluorescence, Gems, Sixth Edition (2006) | |||||||||||||
| Crystallography of Monazite | ||||||||||||||
| Crystal System | Monoclinic, Gemmological Tables (2004) More from other references | |||||||||||||
| Habit | Tabular, prismatic, Gems, Sixth Edition (2006) | |||||||||||||
| Geological Environment | ||||||||||||||
| Where found: | Is found in igneous rocks including granite pegmatites, Gems, Sixth Edition (2006) | |||||||||||||
| Further Information | ||||||||||||||
| Mineral information: | Monazite information at mindat.org | |||||||||||||
| Significant Gem Localities | ||||||||||||||
| ||||||||||||||