Diaboleite is a blue-colored

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

with formula Pb₂CuCl₂(OH)₄. It was discovered in England in 1923 and named ''diaboleite'', from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word διά and boleite, meaning "distinct from boleite". The mineral has since been found in a number of countries.

Description

Diaboleite is deep blue in color and pale blue in transmitted light. The mineral occurs as tabular crystals up to in size, as subparallel aggregates, or it has massive

habit A habit (or wont, as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously. A 1903 paper in the '' American Journal of Psychology'' defined a "habit, from the standpoint of psychology, ...

. Vicinal forms of the tabular crystals have a square or octagonal outline and rarely exhibit pyramidal hemihedralism.

Formation

Diaboleite occurs in manganese oxide ores, as a secondary mineral in

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

and copper oxide ores, and in seawater-exposed

slag The general term slag may be a by-product or co-product of smelting (pyrometallurgical) ores and recycled metals depending on the type of material being produced. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be c ...

. Diaboleite has been found in association with atacamite, boleite, caledonite, cerussite, chloroxiphite, hydrocerussite, leadhillite, mendipite, paratacamite, phosgenite, and wherryite. A study in 1986 synthesized diaboleite crystals up to in size using two different methods. The study demonstrated that diaboleite is a low-temperature phase, that is stable under hydrothermal conditions at temperatures less than . At higher temperatures, the first stable mineral to form is cumengeite.Winchell, p. 934.

History

In 1923, diaboleite was discovered at Higher Pitts Mine in the Mendip Hills of

Somerset Somerset ( , ), Archaism, archaically Somersetshire ( , , ) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by the Bristol Channel, Gloucestershire, and Bristol to the north, Wiltshire to the east ...

, England, and described by L. J. Spencer and E.D. Mountain.Spencer, p. 78. The study of the similar mineral boleite was perplexing at the time and this new mineral only compounded the difficulty. As insufficient material was available for a full investigation, Spencer and Mountain named it ''diaboleite'', meaning "distinct from boleite", out of "desperation".Spencer, p. 79. The mineral was grandfathered as a valid mineral by the

International Mineralogical Association Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. ...

as it was described prior to 1959.

Distribution

, diaboleite has been found in Australia, Austria, Chile, France, Germany, Greece, Iran, Italy, Russia, South Africa, the UK and the US. The type material is held at the

Natural History Museum A natural history museum or museum of natural history is a scientific institution with natural history scientific collection, collections that include current and historical records of animals, plants, Fungus, fungi, ecosystems, geology, paleo ...

in London and the

National Museum of Natural History The National Museum of Natural History (NMNH) is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. With 4.4 ...

in Washington, D.C.

References

;Citations ;Bibliography * *

External links