Kyanite
General
Category	Mineral
Chemical formula	Al2SiO5 (aluminium silicate)
Identification
Color	Blue; also green, white, grey, black
Crystal habit	Columnar; fibrous
Crystal system	Triclinic
Cleavage	[100] Perfect, [010] Imperfect
Fracture	Brittle
Mohs Scale hardness	4. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes WikipediaNaming Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the In Mineralogy, shape and size give rise to descriptive terms applied to the typical appearance or habit of Crystals The many terms used by mineralogists A crystal system is a category of Space groups which characterize Symmetry of structures in three dimensions with Translational symmetry in three directions Cleavage, in Mineralogy, is the tendency of crystalline materials to split along definite planes creating smooth surfaces of which there are several named types In the field of Mineralogy, fracture is a term used to describe the shape and texture of the surface formed when a Mineral is broken The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 5-5 parallel to one axis 6. 5-7 perpendicular to that axis
Luster	Vitreous; Pearly
Refractive index	1. Lustre (or luster) is a description of the way light interacts with the surface of a Crystal, rock, or Mineral. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium 71 - 1. 75
Pleochroism	Trichroic, colorless to pale blue to blue
Streak	White
Specific gravity	3. Pleochroism is an Optical phenomenon in which grains of a rock appear to be different colors when observed at different angles under a Petrographic microscope. The streak (also called powder color) of a Mineral is the Color of the powder produced when it is dragged across an unweathered surface Specific gravity is defined as the ratio of the Density of a given solid or liquid substance to the density of water at a specific temperature and pressure typically 56 - 3. 67
Solubility	None
Diaphaneity	Transparent to translucent

Kyanite from Brazil

Kyanite, whose name derives from the Greek word kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld For the Artificial intelligence Androids of the 1990s Science fiction series Space Above and Beyond, see Silicate (AI A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific WikipediaNaming Pegmatite is a very coarse-grained Igneous rock that has a grain size of 20 mm or more such rocks are referred to as pegmatitic. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Kyanite is a diagnostic mineral of the Blueschist Facies of metamorphic rocks. Blueschist (ˈbluːʃɪst is a rock that forms by the Metamorphism of Basalt and rocks with similar composition at high Pressures and low

Kyanite is a member of the aluminosilicate series, which includes the polymorph andalusite and the polymorph sillimanite. Polymorphism in Materials science is the ability of a solid material to exist in more than one form or Crystal structure Andalusite is an Aluminium nesosilicate Mineral with the chemical formula Al2SiO5 Sillimanite also called Bucholzite is an alumino-silicate Mineral with the Chemical formula Al2SiO5 Kyanite is strongly anisotropic, in that its hardness varies depending on its crystallographic direction. Anisotropy (pronounced with stress on the third syllable ˌænaɪˈsɒtrəpi is the property of being directionally dependent as opposed to Isotropy, which means homogeneity The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material While this is a feature of almost all minerals, in kyanite this anisotropism can be considered an identifying characteristic.

Uses of kyanite

Kyanite is used primarily in refractory and ceramic products, including porcelain plumbing fixtures and dinnerware. It is also used in electrical insulators and abrasives. An interesting property of kyanite is that it undergoes an irreversible expansion when fired at high temperature. Kyanite has also been used as a gemstone, though this use is limited by its anisotropism and perfect cleavage. Kyanite is one of the index minerals that are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism. Finally, as with most minerals, kyanite is a collector's mineral.

Associated minerals

Kyanite is usually found in association with its polymorphs, as well as other silicate minerals. These include:

• andalusite, Al₂SiO₅
• sillimanite, Al₂SiO₅
• quartz, SiO₂
• staurolite, Fe₂Al₉Si₄O₂₂(OH)₂
• micas, AB_2-3(X, Si)₄O₁₀(O,F,OH)₂
• garnets, A₃B₂(SiO₄)₃

Alternative names

Kyanite has several alternative names, including disthene, munkrudite and cyanite. Andalusite is an Aluminium nesosilicate Mineral with the chemical formula Al2SiO5 Sillimanite also called Bucholzite is an alumino-silicate Mineral with the Chemical formula Al2SiO5 Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Staurolite is a red brown to black mostly opaque nesosilicate Mineral with a white streak The word "mica" is thought to be derived from the Latin word la micare, "glitteren" in reference to the brilliant appearance of this mineral (especially The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives White-grey kyanite is also called rhaeticite.

Notes for identification

In Buckingham County, Virginia kyanite from the mine at Mt. There is also Buckingham County Tasmania, a former county in Australia Buckingham County is a county located in the U Willis is transported by train on the Buckingham Branch Railroad. Buckingham Branch Railroad is a Class III short-line Railroad operating over 200 miles (322 km of historic and strategic trackage in Central Virginia

Kyanite's elongated, columnar crystals are usually a good first indication of the mineral, as well as its color (when the specimen is blue). Associated minerals are useful as well, especially the presence of the polymorphs or staurolite, which occur frequently with kyanite. However, the most useful characteristic in identifying kyanite is its anisotropism. If one suspects a specimen to be kyanite, verifying that it has two distinctly different hardnesses on perpendicular axes is a key to identification.

References

• WebMineral Listing
• MinDat Listing
• Mineral Galleries