Fengchengite
Mineral of the eudialyte group
From Wikipedia, the free encyclopedia
Fengchengite is a rare mineral of the eudialyte group[2] with the formula Na12[ ]3(Ca,Sr)6Fe33+Zr3Si(Si25O73)(H2O,OH)3(OH,Cl)2.[3][2] The formula is simplified as it does not show the presence of cyclic silicate groups. When compared to other minerals of the group, fengchengite characterizes in the presence of ferric iron (thus similar to ikranite, mogovidite and feklichevite[2]) and essential, site-dominating vacancies. The mineral was discovered in the Saima complex near Fengcheng city in China – hence its name.[2][3]
CategoryCyclosilicate
FormulaNa12[ ]3(Ca,Sr)6Fe33+Zr3Si(Si25O73)(H2O,OH)3(OH,Cl)2
| Fengchengite | |
|---|---|
| General | |
| Category | Cyclosilicate |
| Formula | Na12[ ]3(Ca,Sr)6Fe33+Zr3Si(Si25O73)(H2O,OH)3(OH,Cl)2 |
| IMA symbol | Fcg[1] |
| Crystal system | Trigonal |
| Crystal class | Hexagonal scalenohedral (3m) H-M symbol: (3 2m) |
| Space group | R3m |
| Unit cell | a = 14.25, c = 30.03 [Å] (approximated) |
| Identification | |
| References | [2][3] |
