Outstanding silver white crystals of this extremely rare cesium mineral nanpingite from the type locality in Nanping, China (Nanping Pegmatite, Yanping District, Nanping, Fujian Province, China Peoples Republic). Very rich specimen for the quantity of nanpingite crystals present. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Nanpingite
Nanpingite is an IMA-recognized mineral species in the silicate class, with the chemical formula CsAl₂(Si₃Al)O₁₀(OH)₂.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Mica structural group.
Key properties: Mohs hardness 2–3; specific gravity 3.11; White streak; Vitreous, pearly on sheets luster; optically biaxial.
IMA symbol Npg, IMA status: approved, named in 1987.
Found in veinlets in the pollucite-rich middle zone of a muscovite-albite-spodumene pegmatite.
It is found associated with Montebrasite, quartz, apatite.
The name refers to its occurrence in the Nanping area, China.