Jun 5 2014
Deerite was first discovered in Laytonville quarry, 5 miles south of Laytonville, Mendocino Co. California in 1964.
It was named after William Alexander Deer, a mineralogist-petrologist at Cambridge University, Cambridge, England.
Properties of Deerite
The following are the key properties of Deerite:
- Cell Data
- Space Group: P21/a
- a = 10.786(8)
- b = 18.88(2)
- c = 9.564(9)
- β = 107:45(5)°
- Z = 4
- Crystal Data
- Monoclinic
- Point Group: 2/m
- Crystals acicular, lozenge-shaped in cross section, to 1mm
- Twinning: Sub-microscopic with twin axis [001], pervasive
- X-ray Powder Pattern: 9.03 (100), 3.01 (70), 2.64 (55), 2.54 (25), 3.22 (20), 2.37 (20), 9.45 (16)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
Content 4 |
| FeO |
36.77 |
34.79 |
35.64 |
40.06 |
| SiO2 |
33.44 |
33.40 |
33.27 |
33.50 |
| SiO2 |
33.44 |
33.40 |
33.27 |
33.50 |
| Fe2O3 |
22.09 |
20.89 |
21.41 |
22.26 |
| H2O |
4.25 |
[4.25] |
[4.25] |
4.19 |
| MnO |
2.86 |
5.72 |
0.74 |
- |
| Al2O3 |
0.92 |
0.16 |
0.41 |
- |
| MgO |
0.15 |
0.25 |
0.64 |
- |
| Total |
100.48 |
[99.46] |
[96.36] |
100.00 |
- Optical Properties
- Optical Class: Biaxial
- Pleochroism: Slight
- X = dark brown
- Y = Z = dark brown-black
- Orientation: Z = c
- α = 1.840(1)
- β = n.d
- γ = 1.870(1)
- 2V(meas.) = n.d
- Estimated Properties
| Electron density |
Bulk density (electron density) = 3.73 g/cm3
note: Specific gravity of Deerite = 3.84 g/cm3 |
| Photoelectric |
PEDeerite = 13.27 barns/electron
U = PEDeerite x ρElectron density = 49.46 barns/cm3 |
| Fermion index |
Fermion index = 0.01
Boson index = 0.99 |
Radioactivity
|
Deerite is not radioactive
|
How to Identify Deerite
Deerite is black in color, with a black-gray luster, and good cleavage. It has a transparent to sub-opaque appearance.
The density of deerite is 3.83 g/cm3, and its hardness is 6.
Global Distribution
Deerite is distributed in the following places:
- Laytonville quarry, at Covelo, California
- Burn's Flats, Mendocino Co.
- Ward Creek, Cazadero, Sonoma Co.
- Panoche Pass, San Benito Co.
- Wild Horse Lookout, Curry Co. Oregon
- Powers quarry, Coos Co.
- Salbertrand, Viaorcia, and Beth-Ghinivert, Piedmont, Italy
- Termignon, Haute-Savoie, France
- Sifnos, Greece
- SÄupÄuren-Karaalan, Eskisehir Province, Turkey
- DiahÄot Valley, and at Ouegoa Koumec, New Caledonia
Occurrence of Deerite and Useful Mineral Association
Deerite occurs in blueschist facies, metasediments formed at low temperature and high pressure. It also occurs in Cu-Fe sulfide deposits and meta-ironstones.
The mineral is closely associated with ferroan kutnohorite, manganoan siderite, aragonite, grunerite, aegirine, quartz, riebeckite, spessartine, stilpnomelane, zussmanite, and howieite.
References