3.7" Rare Andalucite Var Chiastolite Mineral Specimen Asturias Province Boal Spain
Location: Asturias Province, Boal, Spain
Weight: 4.8 Ounces
Dimensions: 3.7 Inches Long, 3.1 Inches Wide, 1.3 Inches Thick
The item pictured is the one you will receive.
Andalucite, a notable mineral within geology and mineralogy, is named after Andalusia, the southern Spanish region where it was originally discovered and documented. This aluminum nesosilicate is distinguished by its unique crystal architecture and forms under well-defined metamorphic conditions. Its occurrence in Spain, especially in Andalusia, has been instrumental in advancing the understanding of its geological environment and its significance as an indicator mineral in metamorphic studies.
Andalucite is one of three polymorphs of the mineral Al2SiO5, alongside kyanite and sillimanite. While they share the same chemical makeup, each has a unique crystal structure that forms under different temperature and pressure conditions. Andalucite commonly develops in medium-grade metamorphic rocks linked to regional metamorphism. Its presence helps geologists identify the specific environmental conditions during rock formation. Crystallizing in an orthorhombic system, andalucite displays prismatic shapes often with square cross-sections. Its colors vary widely—from pink and violet to brown and green—due to trace elements in its structure. The chiastolite variety is distinctive for its dark, cross-shaped carbonaceous inclusions formed by crystal growth patterns that concentrate impurities along certain directions.
