Minerals enriched with lead and zinc in their chemical composition are said to be Zinc and Lead Minerals. Some of the important minerals that contains zinc and lead are as follow:
(1). Galena: PbS
Physical properties of Galena:
- Crystal Systems: Galena is found in the cubic crystal systems.
- Cleavage of Galena: perfect cubic cleavage (cubic cleavage is formed when there are three cleavage plane intersecting at 90 degrees.
- Fracture: Stepped fracture
- The hardness of Galena: 2.5 on Moh’s scale
- Sp.Gr: 7.4 -7.6
- Lustre: Bright metallic.
- Streak: Lead grey
- Habit: Crystals occur as tetrahedra. Also in massive or fibrous habit.
Occurrence: Sphalerite occurs in hydrothermal veins. It is often associated with sphalerite, pyrite, chalcopyrite, etc. It is also associated with silver minerals.
Uses of Galena: Principal ore of lead and silver.
(2). Sphalerite: ZnS2
Physical Properties of Sphalerite:
- Crystal Systems: Sphalerite is found in cubic crystal systems.
- Cleavage: perfect
- Fracture: conchoidal
- Hardness: 3.5 Moh’s scale
- Sp.Gr: 3.9 -4.1
- Lustre: Resinous
- Colour: yellow, brown to black
- Streak: brown to yellow
- Habit: Crystals of Sphalerite occur as tetrahedra. Also massive or fibrous.
Occurrence: Sphalerite occurs in hydrothermal veins. it is often associated with galena and other sulfides.
Uses of Sphalerite:
- Sphalerite is used as a major ore of zinc.
- Sphalerite is also used in galvanized iron, brass and batteries.
- Sphalerite is also used as mildew resistant element in paints and dyes.