Faizievite
From Wikipedia, the free encyclopedia
CategorySilicate mineral, Cyclosilicate
FormulaK2Na(Ca6Na)Ti4Li6Si24O66F2
Dana classification63.2.10.1
| Faizievite | |
|---|---|
| General | |
| Category | Silicate mineral, Cyclosilicate |
| Formula | K2Na(Ca6Na)Ti4Li6Si24O66F2 |
| IMA symbol | Fai[1] |
| Dana classification | 63.2.10.1 |
| Crystal system | Triclinic |
| Crystal class | Pinacoidal (1) (same H-M symbol) |
| Space group | P1 |
| Unit cell | a = 9.82, b = 9.82 c = 17.31 [Å], α = 99.209(2)° β = 94.67(2)°, γ = 119.839(1)° (approximated); Z = 1 |
| Identification | |
| Color | Colorless |
| Crystal habit | tabular plates |
| Cleavage | None |
| Tenacity | Brittle |
| Mohs scale hardness | 4-4.5 |
| Luster | Vitreous |
| Diaphaneity | Opaque |
| Density | 2.83 (measured) |
| Optical properties | Biaxal (+) |
| Refractive index | np=1.65, nm=1.66 (approximated) |
| 2V angle | -72o (measured), -70o (calculated, approximated) |
| References | [2][3] |
Faizievite is a very rare mineral[3] with the formula K2Na(Ca6Na)Ti4Li6Si24O66F2.[2] This triclinic mineral is chemically related to baratovite and katayamalite.[4][5] Faizievite is a single-locality mineral, coming from the moraine of the Darai-Pioz glacier, Tien Shan Mountains, Tajikistan. Alkaline rocks of this site are famous for containing numerous rare minerals, often enriched in boron, caesium, lithium, titanium, rare earth elements, barium, and others.[6]
Faizievite was detected in quartz boulders, together with aegirine, baratovite, fluorite, leucosphenite, pectolite, and polylithionite.[2]
