AM_Stoppaniite
Formula:
(Fe1.22 Al.42 Mg.36) (Be3 Si6) Na.55 (O19 H2)
Name:
Stoppaniite
Unit cell:
9.397 9.397 9.202 90.0 90.0 120.0 , V=703.71
Space group:
P6/MCC (192)
Ferraris G , Prencipe M , Rossi P , European Journal of Mineralogy , 10 (1998) p.491-496, Stoppaniite, a new member of the beryl group: crystal structure, and crystal-chemical implications