May 10 2013
Vanadinite is a member of apatite group of minerals. It was first discovered in 1801 in Zimapan, Hildalgo, Mexico. The mineral was named for the vanadium content in its composition.
Properties of Vanadinite
The following are the key properties of vanadinite:
- Cell Data
- Space Group: P63/m
- a = 10.3174
- c = 7.3378
- Z = 2
- Crystal Data
- Hexagonal
- Point Group: 6/m
- Typically in well-developed hexagonal prismatic crystals, to 14 cm, short to long along [0001], with {1010}, {0001}, modified by {1120}, {1011}, {2021}, {1121}, many others. Commonly cavernous and in parallel groupings; may be acicular, hairlike, fibrous; rarely rounded, globular
- X-ray Powder Pattern: 2.987 (100), 2.995 (92), 3.069 (89), 3.380 (41), 4.470 (35), 3.397 (30), 4.224 (27)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| PbO |
78.07 |
78.80 |
| V2O5 |
19.10 |
19.26 |
| Cl |
2.66 |
2.50 |
| -O = Cl2 |
0.60 |
0.56 |
| P2O5 |
0.30 |
- |
| CaO |
0.07 |
- |
| As2O5 |
trace |
- |
| Total |
99.60 |
100.00 |
- Optical Properties
- Optical Class: Uniaxial (–)
- Absorption: E < O
- ω = 2.416
- ε = 2.350
- Estimated Properties
| Electron density |
Bulk density (electron density)=5.81 g/cm3
note: Specific gravity of Vanadinite =6.95 g/cm3 |
| Photoelectric |
PEVanadinite = 1345.76 barns/electron
U= PEVanadinite x ρElectron density= 7819.15 barns/cm3 |
| Fermion index |
Fermion index = 0.16
Boson index = 0.84 |
| Radioactivity |
Vanadinite is not radioactive |
How to Identify Vanadinite
Vanadinite is either colorless or yellow, brown red, brownish yellow or brown in color. It is non-fluorescent, and has subtranslucent to opaque characteristics, adamantine luster and a brownish yellow streak. The mineral forms conchoidal brittle fractures that produce small, conchoidal fragments. It can be observed in nodular forms, globular forms and prismatic crystals. The hardness of vanadinite ranges from 3.5 to 4, and its average density is 6.94 g/cm3.
Global Distribution
Vanadinite is distributed in the following places:
- Zimapan, Hidalgo
- San Carlos and Los Lamentos, Chihuahua
- Rayon, Sonora, Mexico
- Old Yuma mine, near Tucson, Pima Co.Arizona
- Hamburg, Red Cloud, and North Geronimo mines, Silver district, Arizona
- Puzzler mine, Castle Dome district, Arizona
- Yuma Co., from the Mammoth-St, Arizona
- Anthony mine, Tiger, Pinal Co., Arizona
- Gallagher mine, near Charleston, Cochise Co., Arizona
- Apache mine, Gila Co., at the Western Union mine, Arizona
- Hillsboro and Lake Valley districts, Sierra Co, New Mexico
- Mibladen, at Taouz, and in the Touissit mine, near Oujda, Morocco
- Keban, Turkey
- Abenab, Otavi district, Namibia
- Broken Hill, New South Wales, Australia.
Occurrence of Vanadinite and Useful Mineral Association
Vanadinite occurs as a secondary mineral in the oxidized zone of lead-bearing deposits. It is closely associated with minerals such as barite, calcite, anglesite, cerussite, wulfenite, mottramite, descloizite, pyromorphite and mimetite.
References