Aspidolite

Aspidolite
General
Category	Mica group, phyllosilicate
Formula (repeating unit)	NaMg3AlSi3O10(OH)2
IMA symbol	Asp [1]
Crystal system	Monoclinic
Crystal class	2/m
Space group	C2/m
Unit cell	a = 5.291(8), b = 9.16(2), c = 10.12(2) Å
Identification
Fracture	Micaceous
Optical properties	Biaxial (-)
References	[2]

Aspidolite is a mica group phyllosilicate mineral, the sodium analogue of the magnesium-rich mineral phlogopite. The ideal chemical formula for aspidolite is NaMg₃AlSi₃O₁₀(OH)₂. ^[2]

References

External image
Aspidolite (Kasuga, Japan)

1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
2. Banno, Y.; Miyawaki, R.; Kogure, T.; Matsubara, S.; Kamiya, T.; Yamada, S. (2005). "Aspidolite, the Na analogue of phlogopite, from Kasuga-mura, Gifu Prefecture, central Japan: description and structural data" (PDF). Mineralogical Magazine . 69 (6): 1047–1057. Bibcode:2005MinM...69.1047B. doi:10.1180/0026461056960307. S2CID   131500536.