Andalusite-cordierite schist (Large brown crystals are Andalusite

Andalusite is an aluminium nesosilicate mineral with the chemical formula Al₂SiO₅. Andalusite Source: USGS: USGS-authored or produced data and information are in the public domain File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Andalusite Source: USGS: USGS-authored or produced data and information are in the public domain File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Categories: Mineral stubs | Metamorphic rocks ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... The silicate minerals make up the the largest and most important class of rock-forming minerals. ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ...

The variety chiastolite commonly contains dark inclusions of carbon or clay which form an X or a cross in section. The mineral chiastolite is a variety of Andalusite with the chemical composition Al2OSiO4. ...

Occurrence

Andalusite is a common regional metamorphic mineral which forms under high pressure and/or temperature. The minerals kyanite and sillimanite are polymorphs of andalusite, each occurring under different temperature-pressure regimes and are therefore rarely found together in the same rock. Because of this the three minerals are a useful tool to help identify the pressure-temperature paths of the host rock in which they are found. Metamorphism can be defined as the mineralogical, chemical and crystallographic changes in a solid-state rock, i. ... Kyanite, whose name derives from the Greek, kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. ... Sillimanite: Biotite gneiss (Mesozoic and Paleozoic) Sillimanite is an alumino-sillicate mineral with the chemical formula Al2SiO5. ... In general, a polymorph is something that can exist in several states or forms. ...

It was first reported from Andalucia, Spain. in 1789. Motto: Dominator Hercules Fundator Andaluc a por s , para Espa a y la humanidad (Andalusia for herself, for Spain, and for humanity) Capital Seville Area  - total  - % of Spain Ranked 2nd 87 268 km 17,2% Population  - Total (2003)  - % of Spain  - Density Ranked 1st 7 478 432 17,9% 85,70...

Details

Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... In crystallography, the orthorhombic crystal system is one of the 7 lattice point groups. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... The refractive index of a material is the factor by which the phase velocity of electromagnetic radiation is slowed relative to vacuum. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... It has been suggested that twin boundary be merged into this article or section. ... Pleochroism is an optical phenomenon where due to double refraction of light by a colored gem or crystal, the light is divided into two paths which are polarized at a 90° angle to each other. ...

Related minerals

1. Kyanite
2. Sillimanite
3. Chiastolite

Kyanite, whose name derives from the Greek, kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. ... Sillimanite: Biotite gneiss (Mesozoic and Paleozoic) Sillimanite is an alumino-sillicate mineral with the chemical formula Al2SiO5. ... The mineral chiastolite is a variety of Andalusite with the chemical composition Al2OSiO4. ...

References

• Mineral galleries
• Webmineral
• Mindat w/ locations