May 28 2014
Brontesite was named after Brontes, one of the Cyclopes and a son of Uranus, based on Greek mythology.
Properties of Brontesite
The following are the key properties of Brontesite:
- Cell Data
- Space group: Pnma
- a = 8.434(1)
- b = 15.759(2)
- c = 8.462(1)
- Z = 4
- Crystal Data
- Orthorhombic
- Point group: 2/m2/m2/m
- Crystals tabular on {010}, to 0.1mm
- Pseudotetragonal, exhibiting forms {110}, {011}, {121}
- X-ray powder pattern: 3.067 (100), 2.020 (80), 2.710 (78), 1.910 (78), 2.421 (75), 1.491 (75), 1.457 (65)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| Pb |
47.8 |
47.25 |
| Cl |
36.1 |
40.43 |
| NH4 |
11.3 |
12.32 |
| Br |
3.7 |
- |
| K |
1.1 |
- |
| Total |
100.0 |
100.00 |
- Optical Properties
- Optical Class: Biaxial
- n = 1.70(3)
- Orientation: n.d.
How to Identify Brontesite
Brontesite can be identified in the field by its colorless to white variations. Its translucent form has no cleavage. This mineral has a vitreous luster with white streak.
The density of brontesite is 2.728 g/cm3.
Global Distribution
Brontesite is distributed mainly in La Fossa crater, Vulcano, Aeolian Islands in Sicily, Italy.
Occurrence of Brontesite and Useful Mineral Association
Brontesite occurs as a product of fumarolic activity.
It is often associated with minerals such as bismuthinite, demicheleite-(Cl), demicheleite-(Br), godovikovite, and alunite.
References