Bastnäsite
Pakistan
0.54 carats
© Mineral Classics
Bastnasite is found as dark orange brown to brown crystals.
Gem rough and cut stones are rare.
Bastnäsite Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
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Bastnäsite Gemstones by Size
This table shows distribution of Bastnäsite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.18 cts
Heaviest:6.22 cts
Average:1.76 cts
Total photos:25
Do you have a larger Bastnäsite? Why not upload a photo?
| General Information | ||||||
|---|---|---|---|---|---|---|
| Other Names/Trade Names: | ||||||
| Chemical Formula |
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| Physical Properties of Bastnäsite | ||||||
| Mohs Hardness | 4 to 4.5, Gemmological Tables (2004) More from other references | |||||
| Specific Gravity | 4.78 to 5.20, Gemmological Tables (2004) More from other references | |||||
| Cleavage Quality | Distinct,Poor, Gemstones (2009) Distinct - basal, Poor - prismatic | |||||
| Fracture | Uneven, Gemstones (2009) | |||||
| Optical Properties of Bastnäsite | ||||||
| Refractive Index | 1.72 to 1.82, Gemmological Tables (2004) More from other references | |||||
| Optical Character | Uniaxial/+, Gemmological Tables (2004) More from other references | |||||
| Birefringence | 0.100, Gemmological Tables (2004) More from other references | |||||
| Pleochroism | Weak, Gemstones (2009) | |||||
| Dispersion | Nil, Gemstones (2009) | |||||
| Colour | ||||||
| Colour (General) | Orange-brown, brown, Gemmological Tables (2004) More from other references | |||||
| Transparency | Transparent, Gemmological Tables (2004) More from other references | |||||
| Lustre | Vitreous,Pearly, Gemstones (2009) | |||||
| Crystallography of Bastnäsite | ||||||
| Crystal System | Hexagonal, Gemmological Tables (2004) More from other references | |||||
| Habit | Short prisms, Tabular rounded, Gemstones (2009) | |||||
| Geological Environment | ||||||
| Where found: | Occurs in bauxite deposits, carbonatites and rarely in unusual granites. Sometimes in hydrothermal sources., Gemstones (2009) | |||||
| Further Information | ||||||
| Mineral information: | Bastnäsite information at mindat.org | |||||