Fluckite is an

arsenate mineral Arsenate minerals usually refer to the naturally occurring orthoarsenates, possessing the (AsO4)3− anion group and, more rarely, other arsenates with anions like AsO3(OH)2− (also written HAsO42−) (example: pharmacolite Ca(AsO3OH).2H2O) or ...

with the chemical formula CaMnH₂(AsO₄)₂·2(H₂O). Fluckite's mineral crystallography is

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 ...

meaning it has three axis of different length and three different interior angles that do not equal 90°. Because fluckite possesses three axes with different angles and lengths it is an anisotropic mineral. This means that it has more than one optic axis. This mineral is a member of the P space group meaning that it can be rotated 360° degrees and inverted to obtain the original figure. Optically, this mineral has positive biaxial

birefringence Birefringence, also called double refraction, is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic materials are described as birefrin ...

, which can be shown obtaining an interference figure that is blue in the upper right and lower left quadrants of the figure while looking down the c- axis. Fluckite possesses moderate

optical relief Optical relief (usually noted as simply relief) is a visually observable property in optical mineralogy used to identify minerals based on their refractive index. Relief is determined by observing the degree to which grains stand out from a mounting ...

which is the degree to which the mineral stands out from the mounting medium.

Occurrence

Fluckite was first described in 1980 for an occurrence in the Gabe-Gottes Mine in

Haut-Rhin Haut-Rhin (); Alsatian: ''Owerelsàss'' or '; , . is a department in the Grand Est region, France, bordering both Germany and Switzerland. It is named after the river Rhine; its name means Upper Rhine. Haut-Rhin is the smaller and less pop ...

Alsace Alsace (, ; ) is a cultural region and a territorial collectivity in the Grand Est administrative region of northeastern France, on the west bank of the upper Rhine, next to Germany and Switzerland. In January 2021, it had a population of 1,9 ...

, France,M. Fleischer, L.J. Cabri, G.Y. Chao, and A. Pabst (1980) New Mineral Names*, American Mineralogist, 65,1065-1070. and named for

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 ...

Pierre Fluck of

Louis Pasteur University Louis Pasteur University (, ULP), also known as Strasbourg I, was a large university in Strasbourg, Alsace, France. As of 15 January 2007, there were 18,847 students enrolled at the university, including around 3,000 foreign students. Researc ...

in Strasbourg, France. The mineral was found in at a depth of . It occurs as a post-mine phase on

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

gangue Gangue () is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. It is thus distinct from overburden, which is the waste rock or materials overlying an ore or mineral body that are di ...

. It occurs in association with native arsenic,

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 ...

skutterudite Skutterudite is a cobalt arsenide mineral containing variable amounts of nickel and iron substituting for cobalt with the ideal formula CoAs3. Some references give the arsenic a variable formula subscript of 2–3. High nickel varieties are refe ...

, sainfeldite,

pharmacolite Pharmacolite is an uncommon calcium arsenate mineral with formula CaHAsO4·2(H2O). It occurs as soft, white clusters of fibrous crystals and encrustations which crystallize in the monoclinic system. It is the arsenate analogue of the sulfate minera ...

, villyaellenite,

picropharmacolite Picropharmacolite, Ca4Mg(AsO3OH)2(AsO4)2·11H2O, is a rare arsenate mineral. It was named in 1819 from the Greek for bitter, in allusion to its magnesium content, and its chemical similarity to pharmacolite. The mineral irhtemite, Ca4Mg(AsO3OH ...

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

, dolomite,

ankerite Ankerite, also known as '' brown spar''礦物學名詞: (俄英中对照試用本) Mineralogical Terminology (Russian-English-Chinese version). — Beijing: 中國科学院. 編譯出版委員会 Compilation and Publication Committee of Chinese A ...

and

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

References

{{Reflist Arsenate minerals Calcium minerals Manganese(II) minerals Triclinic minerals Minerals in space group 2