May 20 2014
Arseniosiderite was named by Pierre Armand Petit Dufrenoy in 1842, after the mineral's key elements - arsenic and iron ("sideros" in Greek). It belongs to the mitridatite group.
Properties of Arseniosiderite
The following are the key properties of arseniosiderite:
- Cell Data
- Space group: [A2/a]
- a = 17.76(4)
- b = 19.53(1)
- c = 11.30(1)
- β = 96.0°
- Z = 12
- Crystal Data
- Monoclinic, pseudotetragonal
- Point group: 2/m
- Euhedral crystals very rare, to 2mm
- As flattened fibers, in radial aggregates, and felted to granular masses
- X-ray powder pattern: 8.84 (10), 2.772 (8), 5.62 (5), 2.945 (5), 3.28 (4), 3.22 (4), 2.213 (4)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| As2O5 |
42.67 |
45.94 |
| Fe2O3 |
32.71 |
31.92 |
| CaO |
14.44 |
14.94 |
| H2O |
9.34 |
7.20 |
| MgO |
0.61 |
- |
| insol. |
0.40 |
- |
| PbO |
0.28 |
- |
| FeO |
0.12 |
- |
| Total |
100.57 |
100.00 |
- Optical Properties
- Optical class: Biaxial (-)
- Pseudouniaxial (-)
- Pleochroism: Strong; X = nearly colorless to pale brownish or brownish-red; Y = Z = brownish-red to dark reddish-brown
- Absorption: Y = Z » X
- α = 1.792–1.815; β = 1.870–1.898; γ = 1.870–1.898
- 2V(meas.) = Small
- Estimated Properties
| Electron density |
Bulk density (electron density) = 3.75 g/cm3
note: Specific gravity of arseniosiderite = 3.92 g/cm3 |
| Photoelectric |
PEArseniosiderite = 27.84 barns/electron
U=PEArseniosiderite x ρ electron density = 104.49 barns/cm3 |
| Fermion index |
Fermion index = 0.004956593
Boson index = 0.995043407 |
Radioactivity
|
Arseniosiderite is not radioactive
|
How to Identify Arseniosiderite
Arseniosiderite can be identified in the field by its color variations, such as bronze-brown, yellow, yellow-brown, dark brown, and black. Its translucent to opaque form has {100} good cleavage. This mineral has a sub-metallic luster, with ochraceous streak.
The density of arseniosiderite is 3.5 to 3.9 g/cm3 with a hardness of 1.5 - between talc and gypsum. It is non-fluorescent.
Global Distribution
Arseniosiderite is distributed in the following places:
- France - From Romaneche, Saone-et-Loire
- Germany - At Schneeberg, Saxony, and at Wittichen and Neubulach, Black Forest
- England – At Carrock and Caldbeck Fells, Cumbria; from the Penberthy Croft mine, St. Hilary, Cornwall; in the Huckworthy Bridge mine, Sampford Spiney, Devon
- Austria - At Huttenberg, Carinthia
- Namibia - At Tsumeb
- Australia - Found at the Dome Rock copper mine, about 40km northwest of Mingary, South Australia
- Greece - From the Kamariza mine, Laurium
- Bolivia - In the Negra mine, near Cosca, north of Ollague
- USA - From Sterling Hill, Ogdensburg, Sussex Co. New Jersey; at the Mohawk mine, San Bernardino Co. and in the Kalkar quarry, Santa Cruz, Santa Cruz Co. California; from the Gold Hill mine, Tooele Co. and the Mammoth and other mines, Tintic district, Juab Co. Utah
- Mexico - From the Jesus Maria mine, Mazapil district, Zacatecas; in the Ojuela mine, Mapimi, Durango; and at the Las Animas mine, La Mur, Sonora
Occurrence of Arseniosiderite and Useful Mineral Association
Arseniosiderite occurs as a rare secondary mineral, formed by the oxidation of earlier arsenic-bearing minerals such as scorodite or arsenopyrite.
It is often associated with minerals such as beudantite, arsenopyrite, scorodite, dussertite, carminite, pharmacolite, adamite, erythrite, lollingite, and pitticite.
References