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www.mineralgallery.co.za Minerals A-E |
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Barite |
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Name
Barite
Chemistry
BaSO4, Barium Sulfate
Uses
As a specimen and for extracting barium
Color
Colorless or white, also blue, green, yellow and red shades.
Hardness
6.5-7
Specific gravity
4.5 Very heavy for a translucent mineral
Crystals
It crystallizes in the orthorhombic habit. The crystals are commonly tabular. They may also be prismatic giving a diamond-shaped outline. It sometimes form fibrous or lamelar masses.
Accompanied by:
Calcite, quartz, fluorite, zinc, silver, iron and nickel
Fracture
Uneven
Luster
Vitreous
Cleavage
Basal, perfect: prismatic, very good.
Streak
White
Similar to:
Celestite
Barite is known by the flat tabular crystals.
Barite is a common mineral and makes very attractive specimens. It often is an accessory mineral to other minerals and can make a nice backdrop to brightly colored crystals. At times bladed or tabular crystals of Barite form a concentric pattern of increasingly larger crystals outward. The name comes from the Greek word barytes that means `heavy´
Soft, silver-white, metallic element, symbol Ba, atomic number 56, relative atomic mass 137.33. It is one of the alkaline-earth metals, found in nature as barium carbonate and barium sulphate.
As the sulphate it is used in medicine: taken as a suspension (a `barium meal´), its movement along the gut is followed using X-rays. The barium sulphate, which is opaque to X-rays, shows the shape of the gut, revealing any abnormalities of the alimentary canal.
Barium is also used in alloys, pigments, and safety matches and, with strontium, forms the emissive surface in cathode-ray tubes. It was first discovered in barytes or heavy spar. Because Barite is so common, it can be confused for other minerals. Celestite (SrSO4) has the same structure as barite and forms very similar crystals. The two are indistinguishable by ordinary methods, but a flame test can distinguish them. By scrapping the dust of the crystals into a gas flame the color of the flame will confirm the identity of the crystal. If the flame is a pale green it is barite, but if the flame is red it is celestite. The flame test works because the elements barium (Ba) and strontium (Sr) react in the flame and produce those colors.
The chief ore and most common mineral of barium is barite, barium sulfate. It forms vitreous, white or tinted, tabular or prismatic crystals (orthorhombic system) and crystal aggregates ("desert roses"), as well as coarsely laminated or granular masses, stalactites, and nodules.
Barite mud is used in drilling oil wells to help control oil and gas pressure and prevent drill-hole cave-ins. Barite is the chief component of the white pigment lithopone. Also called heavy spar, it is widespread in metal ore veins, in limestones and in clays formed from weathered limestones, in sandstones, and in extensive beds as a lake or marine deposit.
Barite is a relatively common mineral in the Kalahari Manganese field. It is usually colorless, but can be color-zoned with light brown cores. Associated minerals include pyrite, hematite, rhodochrosite and several other species. Crystals up to 16 cm have been reported from Wessels mine.
Barite at Tsumeb
BaSO4 Forms yellow and amber to brown and dark brown crystals mostly in the areas between a depth of 100 and 300 m. Crystals to 5 cm have been found but the mineral is nevertheless uncommon. Associations commonly include smithsonite or galena.
