3.3" Rare Andalucite Var Chiastolite Mineral Specimen Asturias Province Boal Spain
Location: Asturias Province, Boal, Spain
Weight: 9.2 Ounces
Dimensions: 3.3 Inches Long, 2.3 Inches Wide, 1.7 Inches Thick
The item pictured is the one you will receive.
Andalucite, a key mineral in geological and mineralogical studies, gets its name from the Andalusia region in southern Spain, where it was first identified. This aluminum nesosilicate is known for its unique crystal structure and formation under particular metamorphic conditions. Found especially in Spain, it plays an important role as an indicator mineral for understanding geological settings. Andalucite is one of three Al2SiO5 polymorphs—along with kyanite and sillimanite—each having the same chemical formula but distinct crystal structures stable under varying pressures and temperatures. It generally forms in medium-grade metamorphic rocks linked to regional metamorphism. Its orthorhombic crystals commonly have prismatic shapes with square cross-sections. The color of andalucite ranges from pink, red, and violet to brown, green, or colorless, influenced by trace elements inside the crystal. The chiastolite variety stands out with its characteristic cross-shaped dark carbon inclusions created by impurity patterns during crystal growth.
