Gananite
Encyclopedia
Gananite is a rare bismuth
fluoride
mineral with a general formula of BiF3. Gananite is an isotropic mineral, it belongs to the space group
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. Moreover, this tells us that this mineral is not birefringent. Its color in Plane polarized light is blackish-brown, and it does not show pleochroism
.
. The name is given for its occurrence in the Gannan
region of China. In the Gannan occurrence, the only reported location, it occurs in quartz
vein
s in association with wolframite
, native bismuth, bismuthinite
, pyrite
and chalcopyrite
.
ore. Bismuth is used mainly in chemicals like pharmaceuticals, cosmetics and pigments. Bismuth is also used in creating alloys that have a characteristic low melting point which are used in electronic solders.
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
fluoride
Fluoride
Fluoride is the anion F−, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are...
mineral with a general formula of BiF3. Gananite is an isotropic mineral, it belongs to the space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
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. Moreover, this tells us that this mineral is not birefringent. Its color in Plane polarized light is blackish-brown, and it does not show pleochroism
Pleochroism
Pleochroism is an optical phenomenon in which a substance appears to be different colors when observed at different angles with polarized light.- Background :Anisotropic crystals will have optical properties that vary with the direction of light...
.
Discovery and occurrence
It was first described in 1984 for an occurrence in the Laikeng Mining District, Ganzhou Prefecture, Jiangxi Province, ChinaChina
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. The name is given for its occurrence in the Gannan
Gannan Tibetan Autonomous Prefecture
Gannan Tibetan Autonomous Prefecture is an autonomous prefecture in southern Gansu Province, China. It includes Xiahe and the Labrang Monastery, Luqu, Maqu, and other mostly Tibetan towns and villages...
region of China. In the Gannan occurrence, the only reported location, it occurs in quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
vein
Vein (geology)
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...
s in association with wolframite
Wolframite
Wolframite WO4, is an iron manganese tungstate mineral that is the intermediate between ferberite and huebernite . Along with scheelite, the wolframite series are the most important tungsten ore minerals. Wolframite is found in quartz veins and pegmatites associated with granitic intrusives...
, native bismuth, bismuthinite
Bismuthinite
Bismuthinite is a mineral consisting of bismuth sulfide . It is an important ore for bismuth. The crystals are steel-grey to off-white with a metallic luster...
, pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
and chalcopyrite
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite...
.
Uses
Despite the obscurity of Gananite and its very limited use, it is sometimes used in China as a BismuthBismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
ore. Bismuth is used mainly in chemicals like pharmaceuticals, cosmetics and pigments. Bismuth is also used in creating alloys that have a characteristic low melting point which are used in electronic solders.