Aug 15 2013
Gallite is a tetragonal-scalenohedral gray mineral containing sulfur, gallium and copper. It is a member of chalcopyrite group. The mineral was first discovered in 1958 at Tsumeb, Namibia. It was named based on the presence of gallium in its composition.
Properties of Gallite
The following are the key properties of Gallite:
- Cell Data
- Space Group: I42d
- a = 5.360
- c = 10.49
- Z = 4.
- Crystal Data
- Tetragonal
- Point Group: 42m
- Massive, as minute embedded grains and as exsolution lamellae, to 2 mm. Twinning: Parallel to {112} and {111}
- X-ray Powder Pattern: 3.07 (100), 1.876 (90), 1.610 (90), 1.089 (90), 1.894 (60), 1.215 (60), 1.076 (60).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
Content 4 |
| Cu |
30.8 |
31.2 |
33.5 |
32.19 |
| Ga |
29.2 |
32.4 |
30.2 |
35.32 |
| S |
28.4 |
32.8 |
31.8 |
32.49 |
| Fe |
4.9 |
2.3 |
2.8 |
- |
| Zn |
4.4 |
1.7 |
1.2 |
- |
| Pb |
2.3 |
- |
- |
- |
| Ge |
- |
0.3 |
0.5 |
- |
- Optical Properties
- Estimated Properties
| Electron density |
Bulk density (electron density) = 4.07 g/cm3
note: Specific gravity of Gallite = 4.37 g/cm3 |
| Photoelectric |
PEGallite = 36.07 barns/electron
U= PEGallite x ρElectron density = 146.93 barns/cm3 |
| Fermion index |
Fermion index = 0.002
Boson index = 0.997 |
| Radioactivity |
Gallite is not radioactive. |
How to Identify Gallite
Gallite is an opaque gray mineral having metallic luster and a grayish black streak. The hardness of gallite ranges from 3 to 3.5, and its density is 4.2 g/cm3.
Global Distribution
Gallite is distributed in the following places:
- Tsumeb, Namibia
- Kipushi, 28 km southwest of Lubumbashi, Katanga (Shaba) Province, Congo
- Radka deposit, Pazardzhik, and the Chelopech deposit, Sofia, Bulgaria
- Northwestern Pinar del Rio Province, Cuba
- Yauricocha, Peru.
Occurrence of Gallite and Useful Mineral Association
Gallite occurs in base-metal vein deposits with relatively high gallium content. Tetrahedrite, galena, sphalerite, pyrite, digenite, chalcocite, bornite, germanite and renierite are the minerals closely associated with gallite.
References