Galena, otherwise known as lead glance, represents the natural mineral form of lead sulfide. Galena is an essential ore of lead. Silver is obtained from this ore. Galena was used years ago as the main source of of lead on smelting. Lead is quickly obtained on account of its low melting point.
Deposits of Galena are obtained all over the world in different surroundings. In the beginning of 3000 B.C., attempts were made to determine the content of lead in the ore, which revealed that the ore contained Pyrite, Tennnantite-Tetrahedrite, Sphalerite, Chalcopyrite and the like. Besides, it is also found in skarns (Silicate rocks that are calcium bearing) and in the sedimentary type of rocks where there is a possibility of its replacing carbonate beds and also manifesting in the pores. Initially a fresh crystal is brilliant, later on when exposed to the atmosphere it gets tarnished.
The prominent places where Galena occurs are in USA, Oklahoma-Texas-Missouri; In England, Germany, Mexico, Peru and Zambia
We often find Galena in metaphoric and igneous rocks in the low-to-medium temperatures of hydrothermal veins.
It is obtained in veins in sedimentary rocks, isolated grains, Breccia cements (Rock cemented collectively by a matrix of fine grains), and also as substitutes of Dolostone and Limestone.
In several occasions, silver is obtained in Galena, and therefore, galena is mined for obtaining both silver and lead. Several other commercial minerals that are often obtained along with Galena are Zinc, Antimony and Copper.
Derivation of Name
The Roman environmentalist, Pliny, accepted this name galena for explaining the ore lead.
Chemical Formulae – PbS
Color: grayish-silver to lead, at times bluish hue.
Transparency: Opaque crystals
Cleavage: In all the four directions there is clarity in the cubes.
Luster: In the weathered faces the luster is either dull or metallic.
Fracture: Since the cleavage is perfect the fracture is uneven and hardly visible. They are brittle and normally look like glass or like the majority of non-metallic minerals.
Associated minerals:Pyrite, Sphalerite, Dolomite, Calcite and several other sulfide minerals and minerals oxidized by lead like, Anglesite and Cerussite.
Hardness: (Mohs) – 2 ½
Density: 7.2 to 7.6, with an average of 7.4
Galena is a basic ore in the production of lead, and as such, it is considered a crucial mineral. In addition, it is one of the most important ores of silver. Other than being an ore, its other uses are not many, though this will not be a reason for the reduction of its importance in the world
In the ancient days, Galena was used to make Kohl, a substance for applying about the eyes to bring down the glare caused by the sun in the desert regions and for repelling flies, which was then a vital means causing sickness.
Galena is the initial ore of lead, its principal application is in the manufacture of lead-acid batteries, but, notable quantities are used in the manufacture of lead shots and lead sheets. Galena is frequently mined for the purpose of obtaining silver (e.g. The Galena Mine of the Northern Idaho).
Galena is otherwise known as “potters ore”, because they use it in pottery and is applied for obtaining a green-glaze.
In certain parts of the world, we obtain a large quantity of silver from Galena, certain specimens of this ore are found to contain around 20% silver, on account of which, they are considered silver rich. Besides, Galena was considered as an important ore in the early days for the manufacture of radio devices.