May 15 2013
Nobleite is a transparent mineral containing calcium, boron, hydroxide and water. It was named after Levi Fatzinger Noble (1882-1965), American geologist, for contributing to the geology of the Death Valley region.
Properties of Nobleite
The following are the key properties of Nobleite:
Cell Data
- Space Group: P21/a
- a = 14.56
- b = 8.016
- c = 9.838
- Z = 4
Crystal Data
- Monoclinic
- Point Group: 2/m
- Platyrhombic to pseudohexagonal crystals, to 3 mm as a post mine mammilary coating.
- X-ray powder pattern: 6.79 (100), 3.39 (31), 5.18 (9), 2.566 (9), 3.12 (7), 2.309 (7), 4.68 (5)
Chemical Composition
| Elements |
Content 1 |
Content 2 |
| B2O3 |
60.8 |
61.98 |
| Fe2O3 |
0.15 |
|
| CaO |
16.96 |
16.64 |
| SrO |
0.11 |
|
| Na2O |
0.26 |
|
| K2O |
0.04 |
|
| Li2O |
0.02 |
|
| H2O+ |
20.82 |
|
| H2O- |
1.02 |
|
| H2O |
|
21.38 |
| Insol |
0.08 |
|
| Total |
100.28 |
100 |
Optical Properties
- Optical Class: Biaxial +
- α= 1.500 β = 1.520 γ= 1.554
Estimated Properties
| |
|
| Electron density |
Bulk density (electron density)=2.12 g/cm3
note: Specific gravity of Helvine =2.10 g/cm3 |
| Photoelectric |
PENobleite = 1.73 barns/electron
U=PENobleite x ?Electron Density= 3.66 barns/cc. |
| Fermion index |
Fermion Index = 0.03
Boson Index = 0.97 |
| Radioactivity |
Nobleite is not radioactive |
How to Identify Nobleite
Nobleite is transparent, colorless to white, colorless in transparent light and has white streaks. It has a subvitreous luster and is pearly on cleavages.
Global Distribution
Nobleite is distributed in the USA, in the Furnace Creek district, Death Valley, Inyo Co., California, from 1 km north-northwest of the De Bely mine, and several other places and is found coarsely crystalline in the Corkscrew mine. It is also found in the Sijes district, Salta Province, Argentina.
Occurrence of Nobleite and Useful Mineral Association
Nobleite was found in a recent incrustation produced by weathering of colemanite and priceite veins in altered olivine basalt and basaltic clastic rocks (near the De Bely mine, California, USA). It is associated with minerals Colemanite, meyerhofferite, gowerite, ulexite, ginorite, sassolite, gypsum, manganese oxide (near the De Bely mine, California, USA).
References