Aug 15 2013
Fingerite is a triclinic-pinacoidal black mineral containing vanadium, oxygen and copper. It was first discovered in 1985 from Izalco volcano, El Salvador. The mineral was named after Larry W. Finger, American mineralogist, Carnegie Institution, Washington, D.C., USA.
Properties of Fingerite
The following are the key properties of Fingerite:
- Cell Data
- Space Group: P1
- a = 8.1576(6)
- b = 8.2691(5)
- c = 8.0437(7)
- α = 107.144(5)°
- β = 91.389(7)°
- γ = 106.441(5)°
- Z = 1.
- Crystal Data
- Triclinic
- Point Group: 1
- As crystals, to 150 µm, may be subhedral or anhedral; equant or plate-like
- Twinning: As contact and multiple twins, by rotation about [010]
- X-ray Powder Pattern: 6.48 (100), 3.042 (80), 2.822 (70), 2.025 (70), 3.894 (60), 3.617 (60), 3.293 (60d).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| CuO |
59.3 |
59.53 |
61.59 |
| V2O5 |
39.65 |
39.67 |
38.41 |
| Total |
98.95 |
99.20 |
100 |
- Optical Properties
- Estimated Properties
| Electron density |
Bulk density (electron density) = 4.48 g/cm3
note: Specific gravity of Fingerite = 4.78 g/cm3 |
| Photoelectric |
PEFingerite = 26.34 barns/electron
U = PEFingerite x ρElectron density = 117.86 barns/cm3 |
| Fermion index |
Fermion index = 0.0006
Boson index = 0.9993 |
Radioactivity
|
Fingerite is not radioactive.
|
How to Identify Fingerite
Fingerite is an opaque black mineral having a dark red brown streak and metallic luster.
Global Distribution
Fingerite is widely found in the Izalco volcano, El Salvador.
Occurrence of Fingerite and Useful Mineral Association
Fingerite occurs as a rare component of vanadium-bearing sublimates in fumaroles on a basaltic volcanic cone, formed between 100 and 200°C.
References