Sep 5 2013
Berborite was named after the elements in its composition - Beryllium and Borate.
Properties of Berborite
The following are the key properties of berborite:
- Cell Data
- Space group: P3 (1T)
- a = 4.4328(8)
- c = 5.337(1)
- Z = 1.
OR
- Space group: P63 (2H)
- a = 4.4403(8)
- c = 10.655(2)
- Z = 2.
- Crystal Data
- Hexagonal
- Point group: 3, 3m, or 6
- As crystals showing {0001}, {1011}, {1121}, with half-a-dozen less common forms, typically hemihedral, or prismatic along [0001], to 1.5 cm
- Twinning: Noted, complex
- X-ray powder pattern: 5.35 (100), 2.666 (50), 3.120 (45), 2.046 (20), 3.840 (5), 2.218 (5), 1.780 (5).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| BeO |
39.3 |
44.72 |
| LOI |
33.2 |
- |
| B2O3 |
23.5 |
31.12 |
| Total |
96.0 |
100.00 |
- Optical Properties
- Optical class: Uniaxial (-)
- ω = 1.5804–1.5817
- ε = 1.485–1.4928.
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.05 g/cm3
note: Specific gravity of berborite = 2.06 g/cm3 |
| Photoelectric |
PEBerborite = 0.34 barns/electron
U = PEBerborite x ρ electron density = 0.70 barns/cm3 |
| Fermion index |
Fermion index = 0.17
Boson index = 0.83 |
| Radioactivity |
Berborite is not radioactive.
|
How to Identify Berborite
Berborite can be identified in the field by its colorless form. Berborite's transparent form has {0001} perfect cleavage. This mineral has a vitreous luster with white streak. The fracture on this mineral is uneven to flat. The density of berborite is 2.2 g/cm3 with a hardness of 3 – approximate to calcite.
Global Distribution
Berborite is distributed in the following places:
- Russia - From the Luppikko deposit, Pitkaranta district, Lake Ladoga, Karelia
- Norway - In the Saga and Tuften larvikite quarries, Tvedalen, and at Brønnebukta, Siktesøya Island, Langesundsfjord.
Occurrence of Berborite and Useful Mineral Association
Berborite occurs in serpentinized dolostone associated with W–Sr–B–Be-bearing skarns; and in vugs with natrolite. This mineral is often associated with minerals such hambergite, schoenfliesite, helvite, apatite, cassiterite, fluorite, calcite, dolomite, magnetite, sphalerite, vesuvianite, chondrodite, goethite, diopside, smithsonite, natrolite, and thomsonite.
References