Calumetite is a natural rarely occurring mineral. It was discovered in 1963 at the Centennial Mine near

Calumet, Michigan Calumet ( or ) is a Village (United States), village in the Upper Peninsula of Michigan, Upper Peninsula of the U.S. state of Michigan. The village is located within Calumet Charter Township, Michigan, Calumet Township, Houghton County, Michiga ...

, United States. Calumetite was first discovered along with anthonyite. It has a

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

of .

History

Calumetite was discovered in 1963 at the

Centennial A centennial, or centenary in British English, is a 100th anniversary or otherwise relates to a century. Notable events Notable centennial events at a national or world-level include: * Centennial Exhibition, 1876, Philadelphia, Pennsylvania. ...

Mine Mine, mines, miners or mining may refer to: Extraction or digging *Miner, a person engaged in mining or digging *Mining, extraction of mineral resources from the ground through a mine Grammar *Mine, a first-person English possessive pronoun M ...

. It is named after the locality where it was found. The Centennial Mine is in Houghton County in Calumet, Michigan. The Centennial Mine has produced other copper minerals. Calumetite has been found to occur in

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

cavities; as painting in

canvas Canvas is an extremely durable Plain weave, plain-woven Cloth, fabric used for making sails, tents, Tent#Marquees and larger tents, marquees, backpacks, Shelter (building), shelters, as a Support (art), support for oil painting and for other ite ...

and

frescos Fresco ( or frescoes) is a technique of mural painting executed upon freshly laid ("wet") lime plaster. Water is used as the vehicle for the dry-powder pigment to merge with the plaster, and with the setting of the plaster, the painting becom ...

; and also as

corrosive Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

products on

bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals (such as phosphorus) or metalloid ...

items. It is found in association with

tremolite Tremolite is a member of the amphibole group of silicate minerals with composition Ca2(Mg5.0-4.5Fe2+0.0-0.5)Si8O22(OH)2. Tremolite forms by metamorphism of sediments rich in dolomite and quartz, and occurs in two distinct forms, crystals and fib ...

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 ...

epidote Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in ha ...

monazite Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the cerium ...

copper Copper is a chemical element; it has symbol Cu (from Latin ) 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 pinkish-orang ...

cuprite Cuprite is an oxide mineral composed of copper(I) oxide Cu2O, and is a minor ore of copper. Its dark crystals with red internal reflections are in the isometric system hexoctahedral class, appearing as cubic, octahedral, or dodecahedral forms, ...

atacamite Atacamite is a copper halide mineral: a copper(II) chloride hydroxide with formula Cu2Cl(OH)3. It was first described for deposits in the Atacama Desert of Chile in 1802 by Dmitri de Gallitzin. The Atacama Desert is also the namesake of the min ...

, buttgenbachite,

malachite Malachite () is a copper Carbonate mineral, carbonate hydroxide mineral, with the chemical formula, formula Basic copper carbonate, Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often for ...

paratacamite Paratacamite is a mineral in the halide minerals category. Its chemical formula is . Its name is derived from its association with atacamite. Paratacamite was first described by Herbert Smith in 1906. The zincian endmember is called herbertsmithi ...

, and anthonyite. Calumet, the locality where calumetite was found was once considered a

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

industry. The Centennial Mine produced approximately 37 million pounds of refined copper before it was closed down in 1966 and overtaken.

Physical properties

Calumetite occurs as a brilliant

azure Azure may refer to: Color * Azure (color), a hue of blue ** Azure (heraldry) ** Shades of azure, shades and variations Arts and media * ''Azure'' (Art Farmer and Fritz Pauer album), 1987 * Azure (Gary Peacock and Marilyn Crispell album), 2013 * ...

to powder blue mineral. It has a hardness of 2 with good

cleavage Cleavage may refer to: Science * Cleavage (crystal), the way in which a crystal or mineral tends to split * Cleavage (embryo), the division of cells in an early embryo * Cleavage (geology), foliation of rock perpendicular to stress, a result of ...

along the direction and belongs to the

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic Lattice (group), lattices result from stretching a cubic crystal system, cubic lattice along two of its orthogonal pairs by two different factors, res ...

crystal system In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices (an infinite array of discrete points). Space groups (symmetry groups ...

. Calumetite has a bluish-white streak. Its luster is pearly on cleavage. Calumetite has a

brittle A material is brittle if, when subjected to stress, it fractures with little elastic deformation and without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength. ...

tenacity and is semitransparent. The specific gravity of calumetite could not be measured because of the difficulty in separating the

and

from the calumetite mineral coating them.William A. Sidney (1963) Anthonyite and Calumetite, two new minerals from the Michigan Copper District. The American Mineralogist, 48, 614-619

Geologic occurrence

Calumetite was discovered with Anthonyite in 1963. Other copper minerals have been linked to calumetite which include copper, cuprite, malachite, atacamite, paratacamite, buttgenbachite. The minerals were found in the centennial mine which is known to yield copper minerals. Calumetite has been found in

cavities. Calumetite has been stated to be a naturally occurring mineral. It was prepared with

ammonium chloride Ammonium chloride is an inorganic chemical compound with the chemical formula , also written as . It is an ammonium salt of hydrogen chloride. It consists of ammonium cations and chloride anions . It is a white crystalline salt (chemistry), sal ...

by means of the lime blue recipe which showed that the mineral is synthetic. Calumetite was first discovered in calumet Michigan but has since been observed in other mines near the Calumet mine. It was suggested that calumetite is not a post-mine evaporate because of the mode of occurrence. Calumetite is insoluble in

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

and water, and soluble in cold dilute acids.

Chemical properties and uses

Calumetite has been noted to be useful in paintings on canvas and fresco.Krekel Christopher., Polborn Kurt (2003) Lime Blue: A Mediaeval Pigment for Wall Paintings? Studies in Conservation, 48, 171-182.

References

{{Reflist

External links

Entry on webmineral

Handbook of Mineralogy
Copper(II) minerals Halide minerals Orthorhombic minerals Houghton County, Michigan