Pyrochlore
Pyrochlor
Item-No.: MIN2580 Price: 185.00 EUR
Vishnevye Mts (Vishnyovye; Cherry), Chelyabinsk Oblast', Southern Urals, Urals Region, Russia
| Synonyms: | Azor-phyrrite, Azorpyrrhite, Endeiolite, Fluochlor, Hydrochlor, Niobpyrochlor, Pyrochlor |
| IMA status: | Not recognized, name for a group of niobium dominant members of Pyrochlore Supergroup |
| Classification: | Oxides, Pyrochlor Group |
| Chemical formula: | A2Nb2(O,OH)6Z {A = Na, Ca, Sn2+, Sr, Pb2+, Sb3+, Y, U4+, H2O ; Z = OH, F, O, H2O} |
| Crystal system: | Isometric |
| Density (g/cm3): | 4,2 - 6,4 calculated |
| Tenacity: | splintery |
| Cleavage: | Indistinct on {111} |
| Fracture: | Irregular/uneven, splintery, sub-conchoidal |
| Hardness (Mohs): | 5 - 5,5 |
| Colour: | Brown, yellowish-brown, yellow, greenisch-brown, reddisch-brown, black |
| Lustre: | Vitreous, Resinous |
| Streak: | Yellowish-brown |
| Transparency: | Transparent to opaque |
| Type locality: | Stavern (Fredriksvärn), Larvik, Vestfold, Norway |
| Application: | Source of niobium, tantalum and thorium |