Jun 11 2014
Bieberite was named after the place of first-noted occurrence - Bieber, Germany. It belongs to the melanterite group.
Properties of Bieberite
The following are the key properties of bieberite:
- Cell Data
- Space group: P21/c (synthetic)
- a = 14.040
- b = 6.495
- c = 10.923
- β = 105.27°
- Z = 4
- Crystal Data
- Monoclinic
- Point group: 2/m
- As stalactites, and crusts of minute crystals
- X-ray powder pattern: 4.87 (100), 3.76 (75), 4.82 (55), 2.725 (25), 3.71 (20), 4.02 (14), 3.25 (14)
| Elements |
Content 1 |
Content 2 |
| H2O |
46.83 |
44.86 |
| P2O5 |
29.05 |
28.48 |
| CoO |
19.91 |
26.66 |
| MgO |
3.86 |
- |
| Total |
99.65 |
100.00 |
- Optical Properties
- Optical class: Biaxial (-)
- Orientation: Y = b; Z ∧ c = 29°18’
- α = 1.475–1.477; β = 1.482–1.483; γ = 1.488–1.489
- 2V(meas.) = 88°01’
| Electron density |
Bulk density (electron density) = 1.96 g/cm3
note: Specific gravity of Bieberite = 1.90 g/cm3 |
| Photoelectric |
PE Bieberite = 7.49 barns/electron
U = PE Bieberite x ρ electron density = 14.67 barns/cm3 |
| Fermion index |
Fermion index = 0.0011635864
Boson index = 0.9988364136 |
| Radioactivity |
Bieberite is not radioactive |
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How to Identify Bieberite
Bieberite can be identified in the field by its color variations, such as pinkish-red and flesh pink. Its translucent form has {001} perfect cleavage. This mineral has a vitreous–dull luster, with white streak. The fracture on this mineral is uneven and flat.
The density of bieberite is 1.9 g/cm3, with a hardness of 2 - approximate to gypsum.
Global Distribution
Bieberite is distributed in the following places:
- Germany - From Bieber, near Hanau, Hesse; at Siegen, Westphalia; from Wittichen, Black Forest
- England - In the Penberthy Croft mine, St. Hilary, and at Wheal Alfred, Phillack, Cornwall
- Spain - From Minas de Riotinto, Huelva Province
- Austria - At Leogang, and in the Rauris Valley, Salzburg
- Australia - In the Dome Rock copper mine, South Australia
- Zimbabwe - From the Copper King mine, Lomagundi district
- France - At Chalanches, Isere
- USA - At Island Mountain, Trinity Co. California; from Ajo, Pima Co. Arizona; and in the Dolly prospect, Emery Co. Utah
- Chile - From Tres Puntos, near Copiapo, Atacama
Occurrence of Bieberite and Useful Mineral Association
Bieberite occurs in an uncommon oxidation product of cobalt-bearing sulfide–arsenides.
It is often associated with minerals such as erythrite, annabergite, pharmacolite, linnaeite, and cobaltite.
References