2.8" Rare Andalucite Var Chiastolite Mineral Specimen Asturias Province Boal Spain
Location: Asturias Province, Boal, Spain
Weight: 5.7 Ounces
Dimensions: 2.8 Inches Long, 2 Inches Wide, 1.6 Inches Thick
The item pictured is the one you will receive.
Andalucite, a significant mineral in the geological and mineralogical fields, derives its name from Andalusia, a region in southern Spain where it was first identified and described. This aluminum nesosilicate mineral is characterized by its distinctive crystal structure and its formation under specific metamorphic conditions. Its presence in Spain, particularly in the Andalusian region, has been crucial for understanding its geological context and its role as an indicator mineral.
Andalucite stands out as one of the three fierce polymorphs of Al2SiO5, alongside kyanite and sillimanite. Though chemically identical, these minerals dare to differ in their crystal structures, each thriving under distinct pressures and temperatures. Andalucite boldly forms in medium-grade metamorphic rocks, often at the heart of regional metamorphism. Its very presence challenges geologists, revealing the intense conditions that forged the rock—a powerful clue in unlocking the secrets of Earth's dynamic transformations.
Andalucite crystals, belonging to the orthorhombic system, feature three unequal axes intersecting at right angles, forming striking prismatic shapes often with a square cross-section. This mineral’s captivating color range—from vibrant pinks and reds to subtle greens, browns, and clear tones—is influenced by trace elements that make each specimen unique. Particularly remarkable is the chiastolite variety, known for its eye-catching cross-shaped pattern created by dark carbon inclusions against a lighter backdrop. This distinctive feature results from the crystal’s natural growth, making chiastolite a fascinating and rare addition to any mineral collection.
