Niobite, also known as beta stone, contains 26.6% uranium trioxide, 34.80% niobium pentoxide and 18.30% titanium dioxide. Isometric crystal system, a= 10.32a, symmetric m3m. The crystal is octahedron and diamond dodecahedron. Color brown to black, stripe brown, hardness 4 ~ 5, relative density 3.75 ~ 4.82. Produced in granite pegmatite.
Chemical composition: uranium trioxide 26.6%, niobium pentoxide 34.80%, titanium dioxide 18.30%.
Identification characteristics: the main characteristics are octahedral, tetrahedral and powder diffraction data.
Source: named after Betafo in the democratic republic of Madagascar.
Crystal morphology: hexahedral crystals; It is usually octahedron, but also see the clustering of octahedron m(311) and octahedron o(111).
Crystal system and space group: isometric crystal system, o7h-fd3m;
Cell parameters: a0=10.20-10.42 angstrom, z=8;
Powder crystal data: 2.96(1)1.814(0.45)1.546(0.4)
Brown, light green brown, black. The mineral surface often has a light gray or yellow film. Stripe brown. Grease luster, waxy luster to glass luster or semi - metallic luster. Translucent to opaque. No cleavage. Shell - like fracture, staggered fracture. Crispy. Hardness 3-5.5, specific gravity 3.75-4.82, heating can increase to 5.08.
In tianheshi granite-pegmatite, niobite is associated with microplagioclase, biotite, calcite and thoriite. In the igneous granite pegmatite of aegirinization, there are symbiosis with pyroxene, amphibole, biotite, magnetite, ilmenite and zircon. In addition, in the hydrothermal veins have also been found beta beryl and beryl, thorium uranium ore and monazite symbiosis; The world famous producing areas include the democratic republic of Madagascar (Ambotofotsy,Madagascar) and the kingdom of Norway.
