Aug 14 2013
Aurorite was first discovered from the Aurora mine, Nevada, USA in 1967. The mineral was named after its place of discovery.
Properties of Aurorite
The following are the key properties of Aurorite:
- Cell Data
- Space Group: R3 or R3
- a = 7.514(4)
- c = 20.734(5)
- Z = 2
- Crystal Data
- Hexagonal
- Point Group: 3 or 3.
- As small, irregular masses and platy or scaly grains, to 8 µm
- X-ray Powder Pattern: 6.94 (10), 3.46 (7), 4.06 (5), 2.54 (5), 2.23 (5), 1.429 (5), 2.45 (4)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| MnO2 |
59.99 |
70.5 |
| H2O |
14.78 |
13 |
| MnO |
7.89 |
3.4 |
| Ag2O |
7.5 |
6 |
| BaO |
3.07 |
2.9 |
| CaO |
2.5 |
2.8 |
| PbO |
1.30 |
- |
| K2O |
1.11 |
0.4 |
| CuO |
1.06 |
- |
| ZnO |
0.25 |
0.3 |
| Al2O3 |
0.15 |
0.5 |
| MgO |
0.12 |
- |
| SiO2 |
0.11 |
- |
| FeO |
- |
0.2 |
| As2O5 |
Trace |
| Total |
100 |
100 |
- Optical Properties
- Optical Class: Biaxial
- n = > 2
- 2V(meas.) = n.d
- Anisotropism: Yellow-gray to brownish gray
- Bireflectance: Strong; cream-white to medium black.
- Estimated Properties
| Electron density |
Bulk density (electron density)=3.72 g/cm3
note: Specific gravity of Aurorite =3.87 g/cm3 |
| Photoelectric |
PEAurorite = 31.99 barns/electron
U= PEAurorite x ρ Electron density= 118.99 barns/cm3 |
| Fermion index |
Fermion index = 0.00022
Boson index = 0.99 |
| Radioactivity |
Aurorite is not radioactive |
How to Identify Aurorite
Aurorite is a grayish black or black mineral with an opaque appearance, metallic luster and brown streak. The mineral can be formed as irregular, platy or scaly structures. It has an average density of 3.95 g/cm3, and a hardness ranging from 2 to 3.
Global Distribution
Aurorite is found in the following places:
- Aurora mine, Hamilton, White Pine Co.,USA
- Yucca Mountain, Nye Co., Nevada, USA
- Ash Peak mine, near Duncan, Greenlee Co., from the Sheep Tanks district, La Paz Co.,Morenci
- King of Arizona mine, Kofa district, Yuma Co., Arizona
- Sterling Hill, Ogdensburg, Sussex Co., New Jersey
- Kawazu mine, Shizuoka Prefecture, Japan.
Occurrence of Aurorite and Useful Mineral Association
Aurorite occurs in the veinlets filling microfractures in manganoan calcite. It is closely associated with minerals like quartz, silver, chlorargyrite, pyrolusite, cryptomelane, argentian todorokite and manganoan calcite.
References