May 20 2014
Chalcanthite was named after the Greek word ‘chalkos’, meaning copper, and ‘anthos’, meaning flower.
Properties of Chalcanthite
The following are the key properties of chalcanthite:
- Cell Data
- Space group: P1
- a = 6.110
- b = 10.673
- c = 5.95
- α = 97°35’
- β = 107°10’
- γ = 77°33’
- Z = 2
- Crystal Data
- Triclinic
- Point group: 1
- Uncommonly as short prismatic [001] to thick tabular {111} crystals, exhibiting {100}, {130}, {120}, {110}, {110}, {111}, with 25 other forms noted, to 2cm
- Commonly in stalactitic to reniform crusts, cross-vein fibrous, massive, or granular
- Twinning: Rarely as cruciform intergrowths with {010} common between individuals
- X-ray powder pattern: 4.73 (100), 3.71 (85), 3.99 (60), 3.30 (60), 5.48 (55), 2.749 (50), 2.824 (40)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| H2O |
35.90 |
36.07 |
| SO3 |
32.13 |
32.07 |
| CuO |
31.40 |
31.86 |
| Fe2O3 |
0.76 |
- |
| Total |
100.19 |
100.00 |
- Optical Properties
- Optical class: Biaxial (-)
- Orientation: X (169°,76°); Y (76°,78°); Z (–57°,18°)
- Dispersion: r < v
- α = 1.514; β = 1.537; γ= 1.543
- 2V(meas.) = 56°02’
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.32 g/cm3
note: Specific gravity of chalcanthite = 2.28 g/cm3 |
| Photoelectric |
PE Chalcanthite = 11.43 barns/electron
U=PE Chalcanthite x ρ electron density = 26.52 barns/cm3 |
| Fermion index |
Fermion index = 0.0012460623
Boson index = 0.9987539377 |
Radioactivity
|
Chalcanthite is not radioactive
|
How to Identify Chalcanthite
Chalcanthite can be identified in the field by its color variations, such as green, green-blue, light blue, and dark blue. Its sub-transparent to translucent form has {110} imperfect, {110} indistinct, {111} indistinct cleavage. This mineral has a vitreous luster, with white streak. The fracture on this mineral is conchoidal.
The density of chalcanthite is 2.12 - 2.3 g/cm3 with a hardness of 2.5 – approximate to finger nail. It is non-fluorescent.
Global Distribution
Chalcanthite is distributed in the following places:
- Italy - On Vesuvius, Campania
- Germany - From Rammelsberg and Goslar, Harz Mountains
- Spain - Abundant at Rio Tinto, Huelva
- Chile - from Chuquicamata, at Quetena, near Calama, and Copaquire, Antofagasta
- USA - In Arizona, at the United Verde mine, Yavapai Co. and in the Clifton-Morenci district, Greenlee Co. from the Blue Bird mine, Fierro-Hanover district, Grant Co. New Mexico; commercial amounts in the Bluestone mine, Yerington district, Lyon Co. Nevada; at Butte, Silver Bow Co. Montana; from Ducktown, Polk Co. Tennessee
Occurrence of Chalcanthite and Useful Mineral Association
Chalcanthite occurs in a secondary mineral in the oxidized portions of copper sulfide deposits, commonly of post-mining formation and, rarely, as a fumarolic deposit.
It is often associated with minerals such as melanterite, fibroferrite, rhomboclase, epsomite, morenosite, goslarite, pickeringite, brochantite, gypsum, and retgersite.
References