Oct 11 2013
Calaverite was named after the place of its occurrence - Calaveras Co., California, USA.
Properties of Calaverite
The following are the key properties of calaverite:
- Cell Data
- Space group: C2/m or C2
- a = 7.1947(4)
- b = 4.4146(2)
- c = 5.0703(3)
- β = 90.038(4)°
- Z = 2
- Crystal Data
- Monoclinic
- Point group: 2/m or 2
- Bladed and short to slender prisms elongated k [010], striated k [010], to 1 cm
- Massive, granular
- Twinning: Common on {110}, less common on {031} and {111}
- X-ray powder pattern: 3.02 (10), 2.09 (8), 2.20 (4), 2.93 (3), 1.758 (3), 1.689 (3), 1.506 (3)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| Te |
57.87 |
57.00 |
56.41 |
| Au |
41.66 |
42.15 |
43.59 |
| Ag |
0.77 |
0.60 |
- |
| Total |
100.30 |
99.75 |
100.00 |
- Optical Properties
- Anisotropism: Weak
- R1–R2: (400) 45.7–54.4, (420) 48.4–57.1, (440) 51.1–59.6, (460) 53.6–61.8, (480) 56.0–63.6, (500) 57.9–65.2, (520) 59.4–66.4, (540) 60.6–67.3, (560) 61.3–68.0, (580) 61.8–68.3, (600) 62.2–68.4, (620) 62.5–68.6, (640) 62.7–68.5, (660) 62.8–68.4, (680) 62.9–68.2, (700) 63.0–68.1
- Estimated Properties
| Electron density |
Bulk density (electron density) = 7.58 g/cm3
note: Specific gravity of calaverite = 9.37 g/cm3 |
| Photoelectric |
PECalaverite = 945.97 barns/electron
U=PECalaverite x ρ electron density= 7,174.61 barns/cm3 |
| Fermion index |
Fermion index = 0.04
Boson index = 0.96 |
| Radioactivity |
Calaverite is not radioactive |
How to Identify Calaverite
Calaverite can be identified in the field by its color variations such as yellow and yellowish white. Its opaque form has no cleavage. This mineral has a metallic luster with green streak. The fracture on this mineral is brittle - conchoidal. The density of calaverite is 9.04 g/cm3 with a hardness of 2.5 - approximate to finger nail. It is non-fluorescent.
Global Distribution
Calaverite is distributed in the following places:
- USA - In California, at the Stanislaus [TL], Morgan, and Melones mines, Carson Hill district, Calaveras Co.; at the Spotted Horse mine, Maiden, Fergus Co., and the Mayflower mine, Tobacco Root Mountains, Madison Co., Montana; in Colorado, fine examples in the Cripple Creek district, Teller Co.; the Central City district, Gilpin Co.; Gold Hill, Boulder Co.; and the Bessie G and Mayday mines, La Plata Co
- Mexico - From the San Francisco mine, 145 km north of Hermosillo, Sonora
- Fiji Islands - In the Emperor mine, Vatukoula, and in the Tuvatu Au–Ag–Te deposit, Viti Levu
- Canada - In several mines in the Kirkland Lake area, and in the Hemlo gold deposit, Thunder Bay district, Ontario; and the Robb-Montbray mine, Quebec
- Australia - From the Lake View and North Kalgoorlie mines, Kalgoorlie, Western
- Chile - At the El Indio mine, east of La Serena, Coquimbo
- Japan - At Nishizaki, Gifu Prefecture,in the Date mine, Hokkaido, and the Susaki mine, Shizuoka Prefecture
- Phillipines - At the Bulawan deposit, Negros Occidental
- Russia - From Klyuchi, eastern Siberia, and in the Bereznyakov gold deposit, Southern Ural Mountains
Occurrence of Calaverite and Useful Mineral Association
Calaverite occurs in veins in low-temperature hydrothermal deposits, but also in medium and high-temperature deposits.
It is often associated with minerals such as altaite, krennerite, tennantite, rickardite, arsenopyrite, coloradoite, tetrahedrite, sphalerite, pyrite, stibnite, other sulfides, and other tellurides.
References