Jun 12 2014
Topics Covered
Introduction to Agardite-(Y)
Properties of Agardite-(Y)
How to Identify Agardite-(Y)
Global Distribution
Occurrence of Agardite-(Y) and Useful Mineral Association
References
Introduction to Agardite-(Y)
Chemical Formula - (Y, Ca) Cu6 (AsO4)3(OH)6 •3H2O
Agardite-(Y) was named after Jules Agard, a geologist at the Bureau de Recherches Geologiques et Minieres in Orleans, France. This mineral belongs to the mixite group.
Properties of Agardite-(Y)
The following are the key properties of agardite-(Y):
- Cell Data
- Space group: P63/m
- a = 13.583(2)
- c = 5.895(2)
- Z = 2
- Crystal Data
- Hexagonal
- Point group: 6/m
- Acicular, prismatic
- Elongated along [0001], a few mm long
- X-ray powder pattern:11.73 (10), 2.938 (8), 2.451 (8), 4.43 (7), 3.54 (7), 2.692 (6), 2.558 (6)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| CuO |
45.35 |
44.50 |
| As2O5 |
31.50 |
32.28 |
| H2O |
11.35 |
[10.47] |
| Y2O3 |
7.5 |
4.08 |
| PbO |
- |
4.60 |
| La2O3 |
- |
2.68 |
| CaO |
2.60 |
0.65 |
| RE2O3 |
1.2 |
| Nd2O3 |
- |
1.15 |
| Gd2O3 |
- |
0.62 |
| Ce2O3 |
- |
0.44 |
| Pr2O3 |
- |
0.21 |
| Al2O3 |
- |
0.20 |
| SiO2 |
- |
0.15 |
| Sm2O3 |
- |
0.08 |
| Bi2O3 |
- |
0.04 |
| P2O5 |
- |
0.03 |
| Total |
99.50 |
[102.18] |
- Optical Properties
- Semi-transparent
- Optical class: Uniaxial (+)
- ω = 1.701–1.723
- ε = 1.777–1.815
- Estimated Properties
| Electron density |
Bulk density (electron density) = 3.49 g/cm3
note: Specific gravity of Agardite-(Y) = 3.69 g/cm3 |
| Photoelectric |
PEAgardite-(Y) = 39.59 barns/electron
U = PEAgardite-(Y) x ρ electron density = 264.47 barns/cm3 |
| Fermion index |
Fermion index = 0.00017
Boson index = 0.99982 |
Radioactivity
|
Agardite-(Y) is not radioactive
|
How to Identify Agardite-(Y)
Agardite-(Y) can be identified in the field by its color variations, such as blue-green, and blue. Its translucent form has a vitreous luster, with a greenish-white streak.
The density of agardite-(Y) is 3.66 to 3.72 g/cm3, with a hardness of 3 to 4 - between calcite and fluorite. The mineral is acicular, with spherical and rounded aggregates, and bundled tabular aggregates similar to rose petals.
Global Distribution
Agardite-(Y) is distributed in the following places:
- Spain - From the Luisito mine, Anora, C´ordoba Province
- Germany - At Schneeberg, Saxony; in the Clara mine, near Oberwolfach, Black Forest
- Italy - On Sardinia, from the Santa Lucia and Sa Duchessa mines, near Iglesias
- France - From the Cap Garonne mine, near le Pradet, Var, and Chessy, near Lyon, Rhone
- UK - In Wheal Alfred, Cornwall, England; At the Gwaithyrafon mine, Cwmsymlog, Wales
- Japan - At Hayasi, Setoda, Ikuchi Island, Hiroshima Prefecture
- Australia - From Broken Hill, New South Wales
- USA – From the Tintic district, Juab Co. Utah; in the Mohawk mine, Clark Mountains, San Bernardino Co. California; and at Granite Gap, San Simon district, Hidalgo Co. New Mexico
- Morocco - In the Bou Skour mine, Djebel Sarhro
- Congo - At Mutoshi, Katanga Province
Occurrence of Agardite-(Y) and Useful Mineral Association
Agardite-(Y) occurs in the oxidation zone of some copper deposits.
It is often associated with minerals such as azurite, chrysocolla, malachite, cuprite, copper, quartz, and mimetite.
References