Gananite () is a rare

bismuth Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs ...

fluoride mineral form of

bismuth trifluoride Bismuth(III) fluoride or bismuth trifluoride is a chemical compound of bismuth and fluorine. The chemical formula is BiF3. It is a grey-white powder melting at 649 °C. It occurs in nature as the rare mineral gananite. Synthesis Bismuth fluo ...

with a general formula of BiF₃.Gananite
MinDat.org, accessed 16 December 2010. Gananite is an isotropic mineral, it belongs to the

space group In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it uncha ...

P43m. This means that gananite does not show any colors in cross polarized light, because when polarized light passes through it, it does not split into two perpendicular rays. In other words, because gananite is an isometric mineral, it does not exhibit

double refraction Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic materials are said to be birefringent (or birefractive). The birefring ...

. Moreover, this tells us that this mineral is not

birefringent Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic materials are said to be birefringent (or birefractive). The birefring ...

.Jambor, J. L., Burke, E. A., Ercit, T. S., Grice, J. D. (1988) New mineral names. American Mineralogist, 73, 1492-1499. Its color in plane-polarized light is blackish-brown, and it does not show

pleochroism Pleochroism (from Greek πλέων, ''pléōn'', "more" and χρῶμα, ''khrôma'', "color") is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light. Backgrou ...

Discovery and occurrence

It was first described in 1984 for an occurrence in the Laikeng Mining District,

Gan County Ganxian District () is a district in the municipal region of Ganzhou, Jiangxi Province. Administration Ganxian has an area of . The district executive, legislature and judiciary are at Meilin Town (), just upriver from the prefectural seat, toge ...

, Ganzhou Prefecture, Jiangxi Province, China. The name is given for its occurrence in the Southern Ganzhou (Gannan) region of China. In the Gannan occurrence, the only reported location, it occurs in

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

veins Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...

in association with

wolframite Wolframite is an iron, manganese, and tungstate mineral with a chemical formula of that is the intermediate between ferberite ( rich) and hübnerite ( rich). Along with scheelite, the wolframite series are the most important tungsten ore mineral ...

, native bismuth,

bismuthinite Bismuthinite is a mineral consisting of bismuth(III) sulfide, bismuth sulfide (bismuth, Bi2sulfur, S3). It is an important ore for bismuth. The crystals are steel-grey to off-white with a metallic luster. It is soft enough to be scratched with ...

pyrite The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue giv ...

and

chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mo ...

Uses

Despite the obscurity of gananite and its very limited use, it is sometimes used in China as a

ore.

References

Bismuth minerals Cubic minerals Minerals in space group 218 Fluorine minerals {{halide-mineral-stub