Andalusite and Chiastolite Gemstone

What is Andalusite? Andalusite is a rock-forming mineral that is mined for use in high-temperature refractories. Gem-quality specimens are cut into faceted gems and cabochons. Andalusite forms during the regional metamorphism of shale. It is found in schist and gneiss at some present and ancient convergent plate boundaries where the rocks have been exposed to… Continue reading Andalusite and Chiastolite Gemstone