Alfred Louis Olivier Legrand Des Cloizeaux (17 October 18176 May 1897) was a French
mineralogist
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...
.
Des Cloizeaux was born at
Beauvais
Beauvais ( , ; ) is a town and Communes of France, commune in northern France, and prefecture of the Oise Departments of France, département, in the Hauts-de-France Regions of France, region, north of Paris.
The Communes of France, commune o ...
, in the department of
Oise
Oise ( ; ; ) is a department in the north of France. It is named after the river Oise. Inhabitants of the department are called ''Oisiens'' () or ''Isariens'', after the Latin name for the river, Isara. It had a population of 829,419 in 2019.< ...
. He studied with
Jean-Baptiste Biot
Jean-Baptiste Biot (; ; 21 April 1774 – 3 February 1862) was a French people, French physicist, astronomer, and mathematician who co-discovered the Biot–Savart law of magnetostatics with Félix Savart, established the reality of meteorites, ma ...
at the
Collège de France
The (), formerly known as the or as the ''Collège impérial'' founded in 1530 by François I, is a higher education and research establishment () in France. It is located in Paris near La Sorbonne. The has been considered to be France's most ...
. He became professor of mineralogy at the
École Normale Supérieure
École or Ecole may refer to:
* an elementary school in the French educational stages normally followed by Secondary education in France, secondary education establishments (collège and lycée)
* École (river), a tributary of the Seine flowing i ...
and afterwards at the
Muséum National d'Histoire Naturelle
The French National Museum of Natural History ( ; abbr. MNHN) is the national natural history museum of France and a of higher education part of Sorbonne University. The main museum, with four galleries, is located in Paris, France, within the Ja ...
in
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
. He studied the
geyser
A geyser (, ) is a spring with an intermittent water discharge ejected turbulently and accompanied by steam. The formation of geysers is fairly rare and is caused by particular hydrogeological conditions that exist only in a few places on Ea ...
s of
Iceland
Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...
, and wrote also on the classification of some of the eruptive rocks.
His main work consisted in the systematic examination of the
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
s of numerous minerals, in researches on their
optical
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...
properties and on the subject of
light polarization
, or , is a property of transverse waves which specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. One example of a polarize ...
.
He demonstrated the
circular polarization
In electrodynamics, circular polarization of an electromagnetic wave is a polarization state in which, at each point, the electromagnetic field of the wave has a constant magnitude and is rotating at a constant rate in a plane perpendicular to ...
of
cinnabar
Cinnabar (; ), or cinnabarite (), also known as ''mercurblende'' is the bright scarlet to brick-red form of Mercury sulfide, mercury(II) sulfide (HgS). It is the most common source ore for refining mercury (element), elemental mercury and is t ...
.
[The New international encyclopaedia, Volume 6]
edited by Frank Moore Colby, Talcott Williams
He wrote especially on the means of determining the different
feldspar
Feldspar ( ; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagiocl ...
s,
and is credited with the discovery of
microcline
Microcline (KAlSi3O8) is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during s ...
(a
triclinic
class=skin-invert-image, 180px, Triclinic (a ≠b ≠c ≠a and α, β, γ, 90° pairwise different)
In crystallography, the triclinic (or anorthic) crystal system is one of the seven crystal systems. A crystal system is described by three b ...
potash
Potash ( ) includes various mined and manufactured salts that contain potassium in water- soluble form. -feldspar).
[ He named the minerals ]montebrasite
Amblygonite () is a fluorophosphate mineral, , composed of lithium, sodium, aluminium, phosphate, fluoride and hydroxide. The mineral occurs in pegmatite deposits and is easily mistaken for albite and other feldspars. Its density, cleavage and fl ...
(1871), binnite (a variety of tennantite
Tennantite is a copper arsenic sulfosalt mineral with an ideal formula . Due to variable substitution of the copper by iron and zinc the formula is . It is gray-black, steel-gray, iron-gray or black in color. A closely related mineral, tetrahed ...
) and Christianite (in honor of Christian VIII of Denmark
Christian VIII (18 September 1786 – 20 January 1848) was King of Denmark from 1839 to 1848 and, as Christian Frederick, King of Norway in 1814.
Christian Frederick was the eldest son of Frederick, Hereditary Prince of Denmark, Hereditary Prin ...
). In 1854, Alexis Damour
Augustin Alexis Damour (19 July 1808, in Paris – 22 September 1902, in Paris) was a French mineralogist who was also interested in prehistory.
Biography
In 1827 he studied under Alexandre Brongniart at the Muséum d'Histoire Naturelle in ...
dedicated the mineral descloizite
Descloizite is a rare mineral species consisting of basic lead and zinc vanadium, vanadate, , crystallizing in the orthorhombic crystal system and isomorphous with olivenite. Appreciable gallium and germanium may also be incorporated into the cr ...
in honor of Des Cloizeaux.
Des Cloizeaux was elected as a member of the French Academy of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
in 1869, and was its President in 1889. He was awarded the Wollaston Medal
The Wollaston Medal is a scientific award for geology and the highest award granted by the Geological Society of London, the oldest geological society in the world. The medal is named after William Hyde Wollaston, and was first awarded in 1831. I ...
by the Geological Society of London
The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 Fellows.
Fe ...
in 1886. He was elected as a member to the American Philosophical Society
The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...
in 1878.
See also
* Physical crystallography before X-rays
Physical crystallography before X-rays describes how physical crystallography developed as a science up to the discovery of X-rays by Wilhelm Conrad Röntgen in 1895. In the period before X-rays, crystallography can be divided into three broad are ...
References
External links
Alfred L.O.L. Des Cloizeaux - The Mineralogical Record - Library
{{DEFAULTSORT:Descloizeaux, Alfred
1817 births
1897 deaths
People from Beauvais
French mineralogists
Academic staff of the École Normale Supérieure
Wollaston Medal winners
Foreign members of the Royal Society
Officers of the French Academy of Sciences
Members of the Royal Society of Sciences in Uppsala
International members of the American Philosophical Society