Witherite has dull to vitreous luster. Its Crystals are translucent to transparent. Witherite is a common barium carbonate mineral of the Aragonite group. Witherite may form in very low temperature in hydrothermal environment. It is associated with barite, aragonite and calcite. Witherite is the most common barium mineral. It has always formed TWINS. It is rare because it is easily altered to the sulfate. It is found in pure form and is associated with barite and galena in low temperature hydrothermal veins. It may occur in Scotland and the north of England. It is insoluble in water and soluble in acids.
Occurrence of Witherite
The Witherite mineral occurs in the Penyclum mine. The occurrence of witherite is also seen from localities in central wales and in several mines in Llangynog Orefield.
Further, the occurrence of Whiterite has been identified by mineralogists at localities in Llantrisant area, Dolyhir quarry and in south wales, where fine specimens have been obtained in recent years. In 2002 well crystallized Witherite was obtained. It is mined in Germany, England, Canada and US.
Derivation Of Name
The Witherite mineral was named after an English physician, mineralogist, chemist. William Withering, was the first to describe the mineral.
Harmful For Human Health
In the early 18th century Dr. Leign recorded its harmful effects after the death of a farmer’s wife and child. After this incident, James watt Jr. experimented with the Witherite mineral and observed the same lethal properties. From the 18th century, the farmers of Anglezarke use Witherite as rat poison. Its contact with skin causes irritation.
Color: colorless, white, green, brown, greenish.
Luster is dull to vitreous.
Transparency: Translucent to transparent
Crystal system-is orthorhombic.
Hardness is 3-3.50
Specific gravity: 4.3+
Fracture is uneven.
Streak - white.
Cleavage is distinct in one track.
Witherite is used in the production of glass, cement, soap and enamel ware and synthetic marble. It is also used for hardening steel and refining sugar.