Origin of andalusiteafter Andalusia, where it was discovered
a very hard, orthorhombic silicate of aluminum, AlSiO, usually found in schist, slate, or other metamorphic rocks and used to make various high-temperature materials and as a gem
A hard, grayish white to pinkish brown mineral (Al2SiO5), occurring as nearly square prisms, often with cruciform cross sections, in metamorphic rock.
Origin of andalusiteAfter Andalusia
A hard, grayish white to pinkish brown orthorhombic mineral. Andalusite occurs as nearly square prisms, often with cross-shaped cross sections, in metamorphic rocks. It is a polymorph of kyanite and sillimanite, but forms at shallower depths than they do, and at higher temperatures than kyanite and lower temperatures than sillimanite. Chemical formula: Al2SiO5.
- Garnet, tourmaline, staurolite, andalusite, actinolite, chloritoid or ottrelite, epidote, haematite, and if any of these is abundant its presence may be indicated by the name given the rock, e.g.
- Those rocks which contain andalusite and staurolite are sometimes found in such associations as show that they are due to contact action by intrusive igneous masses.
- In these spotted slates andalusite, chiastolite, garnet and cordierite often occur; chiastolite is especially characteristic; cordierite occurs only where the alteration is intense.