Sep 10 2013
Bischofite is a hydrous magnesium chloride mineral that was first discovered in 1877 from the Leopoldshall and Stassfut, Germany. The mineral was named after Karl Gustav Bischo, German geologist and mineral chemist, University of Bonn, Bonn, Germany.
Properties of Bischofite
The following are the key properties of Bischofite:
- Cell Data
- Space Group: C2/m (synthetic)
- a = 9.8607(2)
- b = 7.1071(2)
- c = 6.0737(2)
- β = 93.758(2)°
- Z = 2
- Crystal Data
- Monoclinic
- Point Group: 2/m
- Crystals short prismatic along [001]; commonly foliated, fibrous, crystalline granular
- Twinning: May twin polysynthetically under pressure
- X-ray Powder Pattern: 4.095 (100), 2.646 (69), 2.880 (58), 2.732 (39), 2.305 (39), 2.228 (27), 3.553 (26)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| H2O |
53.1 |
51.4 |
53.17 |
| Cl |
35.04 |
34.2 |
34.88 |
| Mg |
11.86 |
11.5 |
11.95 |
| SO3 |
- |
2 |
- |
| Ca |
- |
0.9 |
- |
| Total |
100 |
100 |
100 |
- Optical Properties
- Optical Class: Biaxial (+)
- Orientation: X = b; Y ∧ c = 9.5°
- Dispersion: r > v, weak.
- α = 1.495
- β = 1.507
- γ = 1.528
- 2V(meas.) = 79°24'
- Estimated Properties
| Electron density |
Bulk density (electron density)=1.64 g/cm3
note: Specific gravity of Bischofite =1.57 g/cm3 |
| Photoelectric |
PETroilite = 2.58 barns/electron
U= PETroilite x ρ Electron density= 4.22 barns/cm3 |
| Fermion index |
Fermion index = 0.01
Boson index = 0.99 |
| Radioactivity |
Bischofite is not radioactive |
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How to Identify Bischofite
Bischofite is a colorless or white mineral having translucent to transparent appearance, vitreous luster and white streak. It exhibits conchoidal fractures, and it can be formed as massive fibrous or granular structures. The density of bischofite is 1.56 g/cm3, and its hardness ranges from 1.5 to 2.
Global Distribution
Bischofite is distributed in the following places:
- Stassfurt-Leopoldshall, 34 km south of Magdeburg, Saxony-Anhalt, Germany
- Vienenburg and Aschersleben, Lower Saxony. From Lake Inder, Kazakhstan
Occurrence of Bischofite and Useful Mineral Association
Bischofite occurs in saline deposits formed from carnallite. It is closely linked with minerals like kieserite, halite and carnallite.
References