Witherite is a

barium carbonate Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of ...

mineral, Ba C O₃, in the

aragonite Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including pr ...

group. Witherite crystallizes in the

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with ...

system and virtually always is twinned. The mineral is colorless, milky-white, grey, pale-yellow, green, to pale-brown. The

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...

is 4.3, which is high for a translucent mineral. It fluoresces light blue under both long- and short-wave UV light, and is

phosphorescent Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluor ...

under short-wave UV light. Witherite forms in low-temperature

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water ( Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with t ...

environments. It is commonly associated with

fluorite Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs scale ...

, celestine,

galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It cryst ...

barite Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate ( Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), ...

calcite Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratc ...

, and

. Witherite occurrences include: Cave-in-Rock, Illinois, US; Pigeon Roost Mine, Glenwood, Arkansas, US; Settlingstones Mine

Northumberland Northumberland () is a county in Northern England, one of two counties in England which border with Scotland. Notable landmarks in the county include Alnwick Castle, Bamburgh Castle, Hadrian's Wall and Hexham Abbey. It is bordered by land o ...

;

Alston Moor Alston Moor, formerly known as Alston with Garrigill, is a civil parish and electoral ward in Cumbria, England, based around the small town of Alston. It is set in the moorlands of the North Pennines, mostly at an altitude of over 1000 feet. ...

, Cumbria;

Anglezarke Anglezarke is a sparsely populated Civil parishes in England, civil parish in the Borough of Chorley in Lancashire, England. It is an agricultural area used for sheep farming, also site of reservoirs that were built to supply water to Liverpool. T ...

Lancashire Lancashire ( , ; abbreviated Lancs) is the name of a historic county, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significantly. The non-metropolitan county of Lancashi ...

and

Burnhope Burnhope is a village and civil parish in County Durham, England. It is located in the Craghead valley on the opposite side to Stanley and has 1,564 inhabitants, as measured in the 2011 census. Burnhope overlooks Lanchester in the Brown ...

, County Durham, England;

Thunder Bay Thunder Bay is a city in and the seat of Thunder Bay District, Ontario, Canada. It is the most populous municipality in Northwestern Ontario and the second most populous (after Greater Sudbury) municipality in Northern Ontario; its population i ...

area,

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

, Canada, Germany, and

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

(

Tarnowskie Góry Tarnowskie Góry (German: ''Tarnowitz''; szl, Tarnowske Gōry) is a town in Silesia, southern Poland, located in the Silesian Highlands near Katowice. On the south it borders the Upper Silesian Metropolitan Union, a megalopolis, the greater S ...

and Tajno at

Suwałki Region Suwałki Region ( pl, Suwalszczyzna ; lt, Suvalkų kraštas, Suvalkija, russian: cувалкщина, german: Sudauen) is a small region around the city of Suwałki (known in Lithuanian as ''Suvalkai'') in northeastern Poland near the border wit ...

). Witherite was named after

William Withering William Withering FRS (17 March 1741 – 6 October 1799) was an English botanist, geologist, chemist, physician and first systematic investigator of the bioactivity of digitalis. Withering was born in Wellington, Shropshire, the son of a surg ...

(1741–1799) an

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

physician and naturalist who in 1784 published his research on the new mineral. He could show that barite and the new mineral were two different minerals.

Discovery

In 1789 the eminent German geologist

Abraham Gottlob Werner Abraham Gottlob Werner (; 25 September 174930 June 1817) was a German geologist who set out an early theory about the stratification of the Earth's crust and propounded a history of the Earth that came to be known as Neptunism. While most ten ...

named the mineral witherite in honour of William Withering."William Withering (1741-1799): a biographical sketch of a Birmingham Lunatic." M R Lee, ''James Lind Library'', accessed 25 September 2006
/ref> The

Matthew Boulton Matthew Boulton (; 3 September 172817 August 1809) was an English manufacturer and business partner of Scottish engineer James Watt. In the final quarter of the 18th century, the partnership installed hundreds of Boulton and Watt, Boulton & ...

mineral collection of

Birmingham Museum and Art Gallery Birmingham Museum and Art Gallery (BM&AG) is a museum A museum ( ; plural museums or, rarely, musea) is a building or institution that Preservation (library and archival science), cares for and displays a collection (artwork), collection ...

may contain one of the earliest known specimens of witherite. A label in Boulton's handwriting, records: "No.2 Terra Ponderosa Aerata, given me by Dr. Withering”.

Risk to human health

The 18th-century naturalist Dr. Leigh recorded its

lethal Lethality (also called deadliness or perniciousness) is how capable something is of causing death. Most often it is used when referring to diseases, chemical weapons, biological weapons, or their toxic chemical components. The use of this te ...

effects after the death of a farmer's wife and child. James Watt Jnr. experimented with the mineral on animals and he recorded the same lethal properties. Until the 18th century farmers at

used the mineral as rat poison.The Mining Magazine, March 1963, Vol 108, pages 133–139

Industrial use

An experiment conducted by

Josiah Wedgwood Josiah Wedgwood (12 July 1730 – 3 January 1795) was an English potter, entrepreneur and abolitionist. Founding the Wedgwood company in 1759, he developed improved pottery bodies by systematic experimentation, and was the leader in the indus ...

, led to it being used in his '

Jasper ware Jasperware, or jasper ware, is a type of pottery first developed by Josiah Wedgwood in the 1770s. Usually described as stoneware, it has an unglazed matte "biscuit" finish and is produced in a number of different colours, of which the most com ...

'; the mineral had previously been considered as worthless. Witherite has been used for hardening steel, and for making cement, glass, enamelware, soap, dye and explosives. Witherite crystallizes in the

system. The crystals are invariably twinned together in groups of three, giving rise to pseudo-hexagonal forms somewhat resembling bipyramidal crystals of

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical fo ...

, the faces are usually rough and striated horizontally. It transforms into an hexagonal phase at 1084 K that changes into a cubic phase at 1254 K. The mineral is named after

, who in 1784 recognized it to be chemically distinct from

baryte Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate ( Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), a ...

s. It occurs in veins of

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, l ...

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 April ...

Hexham Hexham ( ) is a market town and civil parish in Northumberland, England, on the south bank of the River Tyne, formed by the confluence of the North Tyne and the South Tyne at Warden nearby, and close to Hadrian's Wall. Hexham was the administra ...

, Alston in Cumbria,

, near

Chorley Chorley is a town and the administrative centre of the wider Borough of Chorley in Lancashire, England, north of Wigan, south west of Blackburn, north west of Bolton, south of Preston and north west of Manchester. The town's wealth came ...

and a few other localities. Witherite is readily altered to barium

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

by the action of water containing

calcium sulfate Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates. In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Paris, ...

in solution and crystals are therefore frequently encrusted with

s. It is the chief source of barium

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantiti ...

s and is mined in considerable amounts in Northumberland. It is used for the preparation of rat poison, in the manufacture of

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) o ...

and

porcelain Porcelain () is a ceramic material made by heating substances, generally including materials such as kaolinite, in a kiln to temperatures between . The strength and translucence of porcelain, relative to other types of pottery, arises mainl ...

, and formerly for refining

sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double s ...

. It is also used for controlling the

chromate Chromate or chromat, and their derived terms, may refer to: Chemistry * Chromate and dichromate, ions * Monochromate, an ion * Trichromate, an ion * Tetrachromate, an ion * Chromate conversion coating, a method for passivating metals Biology ...

ratio in

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

electroplating Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...

baths. Witherite-216507.jpg, Two sharp pseudohexagonal crystals of witherite on calcite from

Hardin County, Illinois Hardin County is a county located in the U.S. state of Illinois. According to the 2020 census, it has a population of 3,649, making it the least populous county in Illinois. Its county seat is Elizabethtown. Hardin County is located in the ...

(size: 6.4 x 5.4 x 3.4 cm) Witherite-65711.jpg, Witherite crystal from the Cave-in-Rock Sub-District, Illinois - Kentucky Fluorspar District, Hardin County, Illinois

References

External links

{{commonscat-inline, Witherite Barium minerals Carbonate minerals Orthorhombic minerals Minerals in space group 62 Luminescent minerals Aragonite group

Discovery

Risk to human health

Industrial use

See also

References

External links