Staurolite
Staurolite is a silicate mineral recognized for its hardness and durability, with known Chinese sources.
About Staurolite
Staurolite belongs to the silicate class in the staurolite group and has the chemical formula Fe2+2Al9O6(SiO4)4(OH)2. It crystallizes in the orthorhombic system and ranks among the harder species, with lasting durability.
Identification & care
Crystals commonly develop as prismatic crystals; FAMOUS for cruciform (cross-shaped) penetration twins at 60° and 90°; also isolated crystals without twinning. Its color range is broad, including dark reddish-brown, brownish-yellow, brownish-black, and cross-shaped twins appear black. The luster is vitreous, sub-vitreous, resinous, the streak is whitish to pale brownish-grey, and specimens range from transparent to opaque (most specimens opaque). The cleavage is distinct on {010}. The fracture is subconchoidal, uneven, which aids identification.
Collector context
Collector notes
Among collectors of crystallized species, Staurolite is a recognized reference. Staurolite is widely represented across Chinese provinces, including Yunnan, Sichuan, Inner Mongolia, Tibet.