Wuyi Fluorite Specimen (Zhejiang, China)

Wuyi Fluorite Specimen - Shilonggang (石龙岗) mining area, Shuxi Subdistrict (熟溪街道), Wuyi (武义县) Wuyi Fluorite Field, Jinhua (金华市), Zhejiang (浙江省), China (中国)

The Wuyi fluorite field is among the most significant in China, and this specimen from the Shilonggang area represents a classic example of a low-temperature hydrothermal vein-filling deposit. Its formation is tied to the tectonic and magmatic activity of the Yanshanian orogeny, approximately 140 to 70 million years ago. During this period, hydrothermal fluids rich in fluorine and calcium migrated through fractures in the surrounding acidic volcanic rocks. As the temperature and pressure dropped, these minerals crystallised out of the solution to form the vibrant veins seen today.

From a mineralogical perspective, this specimen displays the signature lavender and deep violet hues that have made Wuyi famous. This coloration is the result of "colour centres" within the crystal lattice, caused by natural radiation or trace impurities that create defects in the arrangement of the atoms. The specimen exhibits a brilliant vitreous lustre and clear crystalline faces. In many Shilonggang samples, the fluorite crystals, which typically form as cubes or octahedrons, are hosted on a contrasting matrix of white microcrystalline Quartz (SiO2). This striking "purple on white" aesthetic is highly prized by collectors. With a Mohs hardness of 4 and four planes of perfect cleavage, the specimen is a textbook example of Fluorite (CaF2) in its natural hydrothermal environment.

Origin: Shilonggang (石龙岗) mining area, Shuxi Subdistrict (熟溪街道), Wuyi (武义县) Wuyi Fluorite Field, Jinhua (金华市), Zhejiang (浙江省), China (中国) (click here for Mindat info)
Mineral type: Fluorite (CaF2)
Size: ~7(L) x 4(H) x 3(W) cm (see scale cube), 157 g