Jun 3 2014
Dreyerite was named after Gerhard Dreyer, Assistant Professor at Johannes Guterberg University in Mainz, Germany, who discovered the mineral from Hirschhorn, near Kaiserlautern, Rhineland-Palatinate, Germany in 1981.
Properties of Dreyerite
The following are the key properties of Dreyerite:
- Cell Data
- Space Group: I41/amd
- a = 7.303(3)
- c = 6.584(3)
- Z = 4
- Crystal Data
- Tetragonal
- Point Group: 4/m 2/m 2/m
- Crystals: platy || {001}, to 0.5mm
- X-ray Powder Pattern: 3.656 (100), 2.739 (60), 4.85 (40), 1.878 (40), 2.918 (20), 2.280 (20), 2.583 (15)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| Bi2O3 |
71.9 |
69.3 |
71.93 |
| V2O5 |
28.55 |
28.8 |
28.07 |
| CaO |
0.9 |
1.0 |
- |
| Total |
101.3 |
99.1 |
100.00 |
- Optical Properties
- Optical Class: Uniaxial (+)
- Pleochroism: O = bright yellow; E = brownish-yellow
- ω = > 2
- ε = > 2
- Estimated Properties
| Electron density |
Bulk density (electron density) = 5.33 g/cm3
note: Specific gravity of Dreyerite = 6.25 g/cm3 |
| Photoelectric |
PEDreyerite = 1221.91 barns/electron
U = PEDreyerite x ρElectron density = 6507.18 barns/cm3 |
| Fermion index |
Fermion index = 0.00048
Boson index = 0.99951 |
Radioactivity
|
Dreyerite is not radioactive
|
How to Identify Dreyerite
Dreyerite can be identified by its orange or brownish-yellow color. It occurs in sheet form, with adamantine luster, yellow streak, and its semi-transparent appearance.
The density of dreyerite is 6.25 g/cm3, and its hardness ranges from 2 to 3.
Global Distribution
Dreyerite is widely distributed from Hirschhorn, near Kaiserlautern, Rhineland-Palatinate, Germany.
Occurrence of Dreyerite and Useful Mineral Association
Dreyerite occurs in rhyolitic tuffs, intercalated with silicified wood and carbonaceous matter.
Quartz, barite, goethite, hematite, kaolinite, chlorargyrite, silver, carnotite, mixite, and bismite are the minerals that are closely associated with dreyerite.
References