1. A hard, typically reddish or brownish mineral composed of aluminum silicate, used in ceramics, refractories, and as a gemstone.
Usage: mineralogy; geology

Examples

• Andalusite is valued in the production of high-temperature ceramics.
• The gemstone variety of andalusite is sometimes called chiastolite when it displays a cross-like pattern.
• Miners extract andalusite from metamorphic rocks in several regions worldwide.
• Andalusite's heat resistance makes it useful in kiln linings and other refractory applications.
• Collectors appreciate andalusite for its pleochroism, which shows different colors when viewed from different angles.