Campigliaite is a

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

and

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

sulfate mineral The sulfate minerals are a class of minerals that include the sulfate ion () within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary mine ...

with a chemical formula of Cu₄Mn(SO₄)₂(OH)₆·4H₂O. It has a chemical formula and also a crystal structure similar to niedermayrite, with Cd(II) cation replacing by Mn(II).Giester, B., Rieck, B., Brandstätter, F. (1998) Niedermayrite, Cu4Cd(SO4)2(OH)·4H2O, a new mineral from the Lavrion Mining District, Greece. Mineralogy and Petrology, 63, 19-34. The formation of campigliaite is related to the

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

sulfide mineral The sulfide minerals are a class of minerals containing sulfide (S2−) or disulfide (S22−) as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, th ...

s to form

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 ...

solutions with ilvaite associated with the presence of

. Campigliaite is a rare secondary mineral formed when metallic sulfide

skarn Skarns or tactites are hard, coarse-grained metamorphic rocks that form by a process called metasomatism. Skarns tend to be rich in calcium-magnesium-iron-manganese-aluminium silicate minerals, which are also referred to as calc-silicate mineral ...

deposits are oxidized. While there are several related associations, there is no abundant source for this mineral due to its rare process of formation. Based on its

crystallographic Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics ( condensed matter physics). The w ...

data and chemical formula, campigliaite is placed in the devillite group and considered the

analogue of devillite.Menchetti, S. and Sabelli, C. (1982
''Campigliaite, Cu4Mn(SO4)2(OH6)·4H2O,a new mineral from Campiglia Marittima, Tuscany, Italy''

American Mineralogist ''American Mineralogist: An International Journal of Earth and Planetary Materials'' is a peer-reviewed scientific journal covering the general fields of mineralogy, crystallography, geochemistry, and petrology. It is an official journal of the Min ...

, 67, 385-393. Campigliaite belongs to the

oxysalt minerals as well followed by the subgroup M=M-T sheets.Eby, R.K. and Hawthorne, F.C. (1993
''Structural Relations in Copper Oxysalt Minerals. I. Structural Hierarchy''
Acta Crystallograph. B49, 28-56 The infinite sheet structures that campigliaite has are characterized by strongly bonded polyhedral sheets, which are linked in the third dimension by weaker hydrogen bonds.

History

S. Menchetti and C. Sabelli discovered campigliaite in one of the side tunnels of the Temperino Mine in

Campiglia Marittima Campiglia Marittima is a ''comune'' (municipality) in the Province of Livorno in the Italian region Tuscany, located about southwest of Florence and about southeast of Livorno. Its toponym has been attested for the first time in 1004 as ''Campi ...

Tuscany it, Toscano (man) it, Toscana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Citizenship , demographics1_footnotes = , demographics1_title1 = Italian , demogra ...

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

. The new mineral was named after its type locality and was approved by the Commission of New Minerals and Mineral Names, International Mineralogical Association.

Structure

When tested with a Weissenberg camera and

single-crystal In materials science, a single crystal (or single-crystal solid or monocrystalline solid) is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no grain boundaries In m ...

diffractometer, campigliaite is found to be twinned with the (100) as its twinning plane. Campigliaite is monoclinic with a point group of 2 and space group of C2. The infinite sheet structures that campigliaite has are characterized by strongly bonded sheets of

polyhedra In geometry, a polyhedron (plural polyhedra or polyhedrons; ) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices. A convex polyhedron is the convex hull of finitely many points, not all on ...

which are linked in the third dimension by the weaker hydrogen bonds.

Physical properties

Campigliaite crystals are

transparent Transparency, transparence or transparent most often refer to: * Transparency (optics), the physical property of allowing the transmission of light through a material They may also refer to: Literal uses * Transparency (photography), a still, ...

with a vitreous luster. Crystals of campigliaite and

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywal ...

are often mixed but small amounts of pure crystals appear to grow on

. Campigliaite crystals are flattened on the {100} and elongated on the 10 These crystals are light or pale blue in color but under light transmission, the crystal color changes to pale greenish blue. The measured density was 3.0 g cm⁻³ by heavy-liquid method but this is uncertain due to the size of the crystals. The calculated density was 3.063 g cm⁻³ with a normalized empirical formula of 7 H₂O.

Geologic occurrence

The formation of campigliaite is related to the

of sulfide minerals to form

solutions with ilvaite associated with the presence of

. Campigliaite is closely associated with

because of the geologic processes that form campigliaite. In addition to the type locality, campigliaite has also been reported from the Biccia Mine in

Alessandria Province The Province of Alessandria ( it, Provincia di Alessandria; pms, Provincia ëd Lissandria; in Piedmontese of Alessandria: ''Provinsa ëd Lissändria'') is an Italian province, with a population of some 425,000, which forms the southeastern part o ...

Piedmont it, Piemontese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

, and from the Deer Trail Mine of the

Tushar Mountains The Tushar Mountains are the third-highest mountain range in Utah after the Uinta Mountains and the La Sal Range. Located in the Fishlake National Forest, Delano Peak, 12,174 ft (3,711 m) NAVD 88, is the highest point in both Beaver and ...

Piute County, Utah Piute County ( ) is a county in south-central Utah, United States. As of the 2010 United States Census, the population was 1,556, making it the second-least populous county in Utah. The county seat is Junction, and the largest town is Circlevil ...

, US.

References

External links

* http://rruff.geo.arizona.edu/AMS/minerals/Campigliaite Sulfate minerals Monoclinic minerals Minerals in space group 5