Jun 13 2014
Barberiite was named after Franco Barberi, Professor of Volcanology at the University of Pisa, Italy. He was instrumental in promoting studies of the Vulcano Island.
It is stable only at ground temperatures, ranging from 200-600°C (392-1112°F). It decomposes in humid conditions.
Properties of Barberiite
The following are the key properties of barberiite:
- Cell Data
- Space group: Pnma
- a = 9.0615(7)
- b = 5.6727(6)
- c = 7.2672(2)
- Z = 4
- Crystal Data
- Orthorhombic
- Point group: 2/m 2/m 2/m
- Crystals: are rare, pseudo hexagonal, tabular to platy on {001}, typically elongated along [010] or [100], to 300µm; commonly in
- globular aggregates, to 2 mm
- X-ray powder pattern: 3.183 (100), 3.540 (90), 2.898 (80), 4.472 (75), 2.163 (70), 2.536 (65), 2.282 (65)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| Na |
0.4 |
- |
| K |
2.2 |
- |
| NH4 |
16.6 |
17.21 |
| BF4 |
79.8 |
82.79 |
| F |
0.3 |
- |
| Cl |
0.6 |
- |
| Br |
0.1 |
- |
| Total |
100 |
100 |
- Optical Properties
- Transparent to translucent
- Color: colorless
- Streak: white
- Luster: Vitreous
- Optical Class: Biaxial (+ ) or (-)
- n = [1.3081]; 2V(meas) = 90(2)°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 1.85 g/cm3
note: Specific gravity of barberiite = 1.86 g/cm3 |
| Photoelectric |
PEBarberiite = 0.52 barns/electron
U = PEBarberiite x ρ electron density = 0.95 barns/cm3 |
| Fermion index |
Fermion index = 0.15
Boson index = 0.85 |
Radioactivity
|
Barberiite is not radioactive
|
How to Identify Barberiite
Barberiite appears as a colorless mineral with a vitreous luster, and a white streak. It is highly soluble in water, and decomposes in humid air.
Global Distribution
Barberiite is found in the Fossa crater in the vulcano, Lipari Islands in Italy.
Occurrence of Barberiite and Useful Mineral Association
Barberiite is formed by fumarolic activity. It is stable at ground temperatures.
It is associated with minerals such as malladrite, realgar, bismuthinite, cannizzarite, sphalarite, galenobismuthite, sulfur, sassolite, and sal ammoniac.
References