Barite - Encyclopedia

    Class : Sulfate
    Subclass : Anhydrous sulfate
    Crystal system : Orthorhombic
    Chemistry : BaS0
4
    Rarity : Really common

Barite (or baryte) is a barium sulfate. Its name comes from the ancient Greek "barus" (heavy) because it is a mineral unusually dense for a non-metallic. It occurs in hydrothermal veins of medium and low temperature where it mixes with the fluorite and various sulfides. Its crystals can take all forms of orthorhombic system. The two most common facies are tabular or lamellar crystals (crested) and elongated crystals (coffins and whistles). The crystals can take various colors, usually white to pinkish, yellow to brown, reddish, greenish, gray-blue or colorless. It is much exploited throughout the world, it is used as a filler in the paper industry, plastics, paints and varnishes. It is also used as heavy mud in oil drilling. It extract the barium from baryte, as used in medical radio-opacifying, recombined into carbonate (BaCO3), barium enters into the composition of some glasses (TV, optical). Finally, it is sometimes cut, but is a simple gem to the collection, its too low hardness and high sensitivity to thermal variations make too brittle material to integrate pieces of jewelry.

Barite on orpiment from Quiruvilca Mine, Peru
Blue barite from Ouichane Mount, Nador, Morocco
Reddish-orange barite from Mashamba West mine, DRC
Faceted barite from Olloix, Puy-de-Dôme, France

Barite in the World

Barite deposits are extremely numerous, the most remarkable are hydrothermal veins. It may be noted colorless crystals, blue or yellow from iron mines of Cumberland in England but also red crystals (realgar inclusions) from Romanian mines. We may also mention blue specimens from La Unión, Spain and white crystals on orange orpiment from Peru. The largest individual crystals discovered exceed the meter at Taouz in Morocco especially. World major producer remains China with its 4.1 billion tons mined in 2005, fantastic specimens coming out now but their geographical traceability is often compromised by an overabundance of operating site and a lack of seriousness in the repertorisation of samples.
Baryte from Châtel-Guyon, Puy-de-Dôme, France
Sceptered barite from Four-la-Brouque, Puy-de-Dôme, France
Barite from Côte d'Abot, Olloix, Puy-de-Dôme, France
Blue barite from Langeac, Haute-Loire, France

Barite in France

France counts among the world's best deposits of barite. The huge brown crystals "with coffin facies" from the Côte d'Abot in Puy-de-Dôme may exceed 20 cm for weight more than 10 kg ! Maine Mine in Saône-et-Loire also produces clusters of spectacular "whistles". Finally, overlooked by the French collectors, it must be emphasized specimens from Saint-Laurent-le-Minier district in Gard which are equally aesthetic : white "balls" of crested barite (pompons) on dark matrix (photo in margin).

In recent years an important discovery took place near La Mure Mine in Isere with groups of transparent colorless crystals with white borders. Probably a little less known but equally interesting, the deposits of Châtel-Guyon (Puy-de-Dôme) with honey color crystals or Four-la-Brouque (Puy-de-Dôme) and these beautiful scepters (photo above). We will finish with the Source du Tambour (Puy-de-Dôme) where baryte associated with bitumen and also gem quality tabular crystals from St. Sandoux (Puy-de-Dôme) with a strong purple pleochroism that make these samples unique.

Twinning

Today, we don't know twin for baryte.

Fakes and scams

Because of its abundance on the Earth's surface and its low resistance to be used in jewelry, it does not exist today synthetic baryte crystals.



Hardness : 3 to 3,5
Density : 4,48
Fracture : Irregular
Trace : White




TP : Transparent to opaque
RI : 1,634 to 1,648
Birefringence :  0,012
Optical character : Biaxial +
Pleochroism : None to strong
Fluorescence : White to pale green


Solubility : Insoluble

Magnetism : None
Radioactivity : None