2.3" Rare Andalucite Var Chiastolite Mineral Specimen Asturias Province Boal Spain

Location: Asturias Province, Boal, Spain

Weight: 2 Ounces 

Dimensions:  2.3 Inches Long, 1.2 Inches Wide, 0.8 Inches Thick

The item pictured is the one you will receive. 

Andalucite, an important mineral in geology and mineralogy, takes its name from Andalusia in southern Spain, where it was first discovered and studied. This aluminum nesosilicate is notable for its unique crystal structure and forms under particular metamorphic conditions. Found in Spain, especially in Andalusia, it plays a key role in revealing the geological history of the area and serves as an important indicator mineral.

Andalucite is one of three polymorphs of Al2SiO5, alongside kyanite and sillimanite. While they share the same chemical makeup, their crystal structures vary and form under different pressure and temperature conditions. Typically found in medium-grade metamorphic rocks linked to regional metamorphism, andalusite provides valuable insights into the specific pressure and temperature during rock formation. Its orthorhombic crystals have three unequal, perpendicular axes and often appear prismatic with square cross-sections. Colors range from pink, red, and violet to brown, green, or colorless due to trace elements. The chiastolite variety is especially striking, showing a unique cross-shaped pattern from dark carbon inclusions within the mineral.