Sillimanite
Sillimanite is a silicate mineral prized by collectors for its exceptional color range, with known Chinese sources.
About Sillimanite
Sillimanite is classified as a silicate mineral in the sillimanite group (with kyanite and andalusite) and has the chemical formula Al2SiO5. It crystallizes in the orthorhombic system and is one of the most visually varied minerals in the collector market.
Identification & care
Specimens usually show long prismatic, fibrous crystals ('fibrolite'); columnar; radiating; rarely distinct crystals. Its color range is broad, including white, pale brown, gray, grayish green, and gem varieties: blue or violet (rare). The luster is vitreous, silky (fibrous variety), the streak is white, and specimens range from transparent to translucent. The cleavage is perfect on {010}. The fracture is subconchoidal, which aids identification.
Collector context
Collector notes
For collectors, Sillimanite is a benchmark crystalline species. Sillimanite is widely represented across Chinese provinces, including Fujian, Heilongjiang, Anhui, Hebei.