Anthonyite is a hydrous secondary copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 halide mineral

Halide mineral

The halide mineral class include those minerals with a dominant halide anion . Complex halide minerals may also have polyatomic anions in addition to or that include halides.Examples include the following:*Halite NaCl*Sylvite KCl...

 with chemical formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 of Cu(OH,Cl)₂•3(H₂O).

It was discovered in 1963 in the Centennial mine, Calumet

Calumet, Michigan

Calumet is a village in Calumet Township, Houghton County, in the U.S. state of Michigan's Upper Peninsula, that was once at the center of the mining industry of the Upper Peninsula. Also known as Red Jacket, the village includes the Calumet Downtown Historic District, listed on the National...

, Houghton County, Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

, USA. It was discovered by the University of Arizona

University of Arizona

The University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...

 mineralogist John W. Anthony (1920–1992), who named it for himself.

Anthonyite is lavender in color, has a Mohs hardness of 2 and crystallizes in the monoclinic crystal system

Crystal system

In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals...

.

Anthonyite occurs as an alteration of native copper

Native copper

Copper, as native copper, is one of the few metallic elements to occur in uncombined form as a natural mineral, although most commonly occurs in oxidized states and mixed with other elements...

 in basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

 in fractures and cavities by circulation of chloride rich groundwater or connate fluids. The similar orthorhombic mineral calumetite

Calumetite

Calumetite is a natural rarely occurring mineral. It was discovered in 1963 at the Centennial Mine near Calumet, Michigan, United States. Calumetite was first discovered along with anthonyite. It has a chemical formula of Cu2•2.-History:...

 occurs by the same process.
It occurs associated with tremolite

Tremolite

Tremolite is a member of the amphibole group of silicate minerals with composition: Ca2Mg5Si8O222. Tremolite forms by metamorphism of sediments rich in dolomite and quartz. Tremolite forms a series with actinolite and ferro-actinolite. Pure magnesium tremolite is creamy white, but the color grades...

, quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

, epidote

Epidote

Epidote is a calcium aluminium iron sorosilicate mineral, Ca2Al2O, crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often...

, monazite

Monazite

Monazite is a reddish-brown phosphate mineral containing rare earth metals. It occurs usually in small isolated crystals. There are actually at least four different kinds of monazite, depending on relative elemental composition of the mineral:...

, native copper

Native copper

Copper, as native copper, is one of the few metallic elements to occur in uncombined form as a natural mineral, although most commonly occurs in oxidized states and mixed with other elements...

, cuprite

Cuprite

Cuprite is an oxide mineral composed of copper 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, or in combinations. Penetration twins frequently occur...

 and paratacamite in the Centennial mine area.
It also occrs in the Cole mine, at Bisbee

Bisbee

Bisbee may refer to:* Bisbee, Arizona* Bisbee, North Dakota* Bisbee Blue, turquoise from Bisbee, Arizona.* Bisbee Deportation, the illegal expulsion of 1,300 miners from Bisbee, Arizona...

, Cochise County, Arizona

Cochise County, Arizona

-2010:Whereas according to the 2010 U.S. Census Bureau:*78.5% White*4.2% Black*1.2% Native American*1.9% Asian*0.3% Native Hawaiian or Pacific Islander*4.0% Two or more races*9.6% Other races*32.4% Hispanic or Latino -2000:...

; and Villa Hermosa

Villa Hermosa

Villa Hermosa is a town in the La Romana province of the Dominican Republic.- Sources :* – World-Gazetteer.com...

, Sonora

Sonora

Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....

, Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. It occurs as a slag

Slag

Slag is a partially vitreous by-product of smelting ore to separate the metal fraction from the unwanted fraction. It can usually be considered to be a mixture of metal oxides and silicon dioxide. However, slags can contain metal sulfides and metal atoms in the elemental form...

 mineral in Richelsdorf, Hesse

Hesse

Hesse or Hessia is both a cultural region of Germany and the name of an individual German state.* The cultural region of Hesse includes both the State of Hesse and the area known as Rhenish Hesse in the neighbouring Rhineland-Palatinate state...

, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 and Laurium

Laurium

Laurium or Lavrio is a town in southeastern part of Attica, Greece. It is the seat of the municipality of Lavreotiki...

, Greece

Greece

Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

.