2.6" Rare Andalucite Var Chiastolite Mineral Specimen Asturias Province Boal Spain
Location: Asturias Province, Boal, Spain
Weight: 1.7 Ounces
Dimensions: 2.6 Inches Long, 1.6 Inches Wide, 0.7 Inches Thick
The item pictured is the one you will receive.
Andalucite is a key mineral in geology, named after Andalusia in southern Spain, where it was first discovered. This aluminum nesosilicate stands out with its unique crystal structure, formed under specific metamorphic conditions. Found especially in Spain, Andalucite plays a crucial role in revealing the geological history of the region. As one of three Al2SiO5 polymorphs, along with kyanite and sillimanite, it shares the same chemical makeup but differs in crystal structure, stable under distinct pressure and temperature conditions. Its formation in medium-grade metamorphic rocks makes Andalucite an essential indicator for understanding the pressure and temperature during rock formation, offering invaluable insights for geologists.
Andalucite crystals belong to the orthorhombic system, with three unequal, perpendicular axes shaping their form. They often appear as prismatic crystals featuring a bold square cross-section. The mineral’s colors boldly span from pink, red, and violet to shades of brown, green, and even clear, reflecting the influence of trace elements locked inside. Chiastolite, a daring variety of andalucite, stands out with striking dark carbon-rich inclusions arranged in a dramatic cross pattern. This unique design results from the crystal’s growth process, where impurities carve distinct paths along specific crystal directions.
