May 28 2014
Wheatleyite is a triclinic-pinacoidal blue mineral, containing sodium, oxygen, hydrogen, copper, and carbon. It was first observed in the Wheatley mine, near Phoenixville, Chester Co. Pennsylvania, USA. It was named for the locality.
Properties of Wheatleyite
The following are the key properties of Wheatleyite:
- Cell Data
- Space Group: P1
- a = 7.559(3)
- b = 9.665(4)
- c = 3.589(1)
- α = 76.65(2)°
- β = 103.67(2)°
- γ = 109.10(2)°
- Z = 1
- Crystal Data
- Triclinic
- Point Group: 1
- Thin acicular crystals, to 2mm, in aggregates
- Twinning: Observed on an undetermined law
- X-ray Powder Pattern: 6.539 (10), 3.169 (9), 7.04 (100), 3.655 (5), 2.799 (4), 2.538 (3), 2.497 (3)
- Chemical Composition
| Elements |
Content |
| C2O3 |
44.79 |
| CuO |
24.73 |
| Na2O |
19.27 |
| H2O |
11.21 |
| Total |
100 |
- Optical Properties
- Biaxial (+)
- Pleochroism: X = colorless
- Y = very pale blue
- Z = intense dark blue
- Dispersion: r < v, moderate
- Absorption: Z > Y > X
- α = 1.400(4)°
- β = 1.499(2)°
- γ = 1.667(2)°
- 2V(meas.) = 83(5)°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.24 g/cm3
note: Specific gravity of Wheatleyite = 2.27 g/cm3 |
| Photoelectric |
PEWheatleyite = 8.83 barns/electron
U = PEWheatleyite x ρElectron density = 19.82 barns/cm3 |
| Fermion index |
Fermion index = 0.0018
Boson index = 0.9981 |
Radioactivity
|
Wheatleyite is not radioactive
|
How to Identify Wheatleyite
Wheatleyite is generally found to have a blue color, with perfect cleavage. It has a transparent appearance, light blue streak, and vitreous luster.
The density of wheatleyite is 2.27 g/cm3, and its relative hardness ranges from 1 to 2.
Global Distribution
Wheatleyite is widely distributed in the Wheatley mine, near Phoenixville, Chester Co. Pennsylvania, USA.
Occurrence of Wheatleyite and Useful Mineral Association
Wheatleyite is a very rare mineral, occurring on the mine dumps of a Pb–Zn vein deposit.
It is commonly associated with quartz, cerussite, galena, and sphalerite.
References