EntityQ3632377· pop 10· linked from 6 articles

babefphite

Babefphite is a rare phosphate mineral with the general formula BaBe(PO4)(F,OH). The name is given for its composition (Ba meaning barium, Be meaning beryllium, F meaning fluorine, and P for phosphorus).

Key facts

Mineral.name: Babefphite
Mineral.category: Phosphate mineral
Mineral.formula: BaBe(PO4)(F,OH)
Mineral.IMAsymbol: Bbf
Mineral.strunz: 8.BA.15
Mineral.system: Triclinic
Mineral.class: Pedial (1) (same H-M symbol)
Mineral.symmetry: F1
Mineral.unit cell: a = 6.889 Å, b = 16.814 Å, c = 6.902 Å; α = 90.01°, β = 89.99°, γ = 90.32°; Z = 8
Mineral.color: White
Mineral.habit: As anhedral, equant to flattened grains, to 1.5 mm; may be in aggregates, (pseudotetragonal)
Mineral.tenacity: Brittle
Mineral.mohs: 3.5
Mineral.luster: Vitreous
Mineral.refractive: nω = 1.629 nε = 1.632
Mineral.opticalprop: Uniaxial (+) – biaxial positive (pseudouniaxial)
Mineral.birefringence: 0.003
Mineral.streak: White

via Wikipedia infobox

Article

4 sections

Contents

Crystallography
Optical properties
Occurrence
References

==Crystallography== Babefphite is tetragonal, which means crystallographically, it contains two horizontal and interchangeable equal axes (a1 and 2) and a longitudinal axis (c). It belongs to the 4/m 2/m 2/m point group; meaning it has four horizontal axes of twofold symmetry, two of which coincide with the crystallographic axes (a1) and (a2) and the remaining two at 45° to the (a1) and (a2).