Malachite
Overview
 
Malachite is a copper carbonate mineral, with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

  Cu
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...

2CO3
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

(OH)
Hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and a hydrogen atom held together by a covalent bond, and carrying a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, as a ligand, a nucleophile, and a...

2. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal
Botryoidal
A botryoidal texture or mineral habit is one in which the mineral has a globular external form resembling a bunch of grapes as derived from the Greek. This is a common form for many minerals particularly hematite where it is the classically recognized shape. It is also a common form of goethite,...

, fibrous, or stalagmitic
Stalagmite
A stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. This stalagmite formation occurs only under certain pH conditions within the underground cavern. The corresponding formation on...

 masses. Individual crystals are rare but do occur as slender to acicular
Acicular (crystal habit)
Acicular, in mineralogy, refers to a crystal habit composed of a radiating mass of slender, needle-like crystals. Minerals with this habit tend to be fragile and complete, undamaged specimens can be uncommon.-Examples:...

 prisms. Pseudomorph
Pseudomorph
In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical form , resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced by another...

s after more tabular or blocky azurite
Azurite
Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...

 crystals also occur.
The stone's name derives (via Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

: molochītis, Middle French
Middle French
Middle French is a historical division of the French language that covers the period from 1340 to 1611. It is a period of transition during which:...

: melochite, and Middle English
Middle English
Middle English is the stage in the history of the English language during the High and Late Middle Ages, or roughly during the four centuries between the late 11th and the late 15th century....

 melochites) from Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 Μολοχίτης λίθος molochitis lithos, "mallow-green stone", from μολόχη molōchē, variant of μαλάχη malāchē, "mallow".
Discussions
Encyclopedia
Malachite is a copper carbonate mineral, with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

  Cu
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...

2CO3
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

(OH)
Hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and a hydrogen atom held together by a covalent bond, and carrying a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, as a ligand, a nucleophile, and a...

2. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal
Botryoidal
A botryoidal texture or mineral habit is one in which the mineral has a globular external form resembling a bunch of grapes as derived from the Greek. This is a common form for many minerals particularly hematite where it is the classically recognized shape. It is also a common form of goethite,...

, fibrous, or stalagmitic
Stalagmite
A stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. This stalagmite formation occurs only under certain pH conditions within the underground cavern. The corresponding formation on...

 masses. Individual crystals are rare but do occur as slender to acicular
Acicular (crystal habit)
Acicular, in mineralogy, refers to a crystal habit composed of a radiating mass of slender, needle-like crystals. Minerals with this habit tend to be fragile and complete, undamaged specimens can be uncommon.-Examples:...

 prisms. Pseudomorph
Pseudomorph
In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical form , resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced by another...

s after more tabular or blocky azurite
Azurite
Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...

 crystals also occur.

Etymology and history

The stone's name derives (via Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

: molochītis, Middle French
Middle French
Middle French is a historical division of the French language that covers the period from 1340 to 1611. It is a period of transition during which:...

: melochite, and Middle English
Middle English
Middle English is the stage in the history of the English language during the High and Late Middle Ages, or roughly during the four centuries between the late 11th and the late 15th century....

 melochites) from Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 Μολοχίτης λίθος molochitis lithos, "mallow-green stone", from μολόχη molōchē, variant of μαλάχη malāchē, "mallow". The mineral was given this name due to its resemblance to the leaves of the Mallow plant
Malva
Malva is a genus of about 25–30 species of herbaceous annual, biennial, and perennial plants in the family Malvaceae , one of several closely related genera in the family to bear the common English name mallow. The genus is widespread throughout the temperate, subtropical and tropical regions of...

.. In turn, the stone's Greek name may be borrowed from the Hebrew word: מלך Melekh (with root letters: M-L-KH) which means: king-since the stone was considered royal and was used by royalty and Arabic (ملك Malak or Malek". Hence, this stone's Hebrew name is; מלכי Malakhi and, in Arabic: الملكيت (al) Malkit-(the) Malchite (stone).

Malachite was used as a mineral pigment in green paints from antiquity until about 1800. The pigment is moderately lightfast, very sensitive to acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

s and varying in color. The natural form was being replaced by its synthetic form, verditer amongst other synthetic greens. It is also used for decorative purposes, such as in the Malachite Room in the Hermitage
Hermitage Museum
The State Hermitage is a museum of art and culture in Saint Petersburg, Russia. One of the largest and oldest museums of the world, it was founded in 1764 by Catherine the Great and has been opened to the public since 1852. Its collections, of which only a small part is on permanent display,...

, which features a large malachite vase. "The Tazza
Tazza
A tazza is a shallow saucer-like dish either mounted on a stem and foot or on a foot alone. The word has been generally adopted by archaeologists and connoisseurs for this type of vessel, used either for drinking, serving small items of food, or just for display.The Farnese Tazza is a 2nd century...

", one of the largest pieces of malachite in North America and a gift from Tsar Nicholas II, stands as the focal point in the center of the room of Linda Hall Library
Linda Hall Library
The Linda Hall Library is a privately-endowed American library of science, engineering and technology located in Kansas City, Missouri, about a "five-minute walk from Kansas City’s Nelson-Atkins Museum of Art." It is the "largest independently funded public library of science, engineering and...

.

Occurrence and historical uses

Malachite often results from weathering of 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...

 ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

s and is often found together with azurite
Azurite
Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...

 (Cu3(CO3)2(OH)2), goethite
Goethite
Goethite , named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low-temperature environments. Goethite has been well known since prehistoric times for its use as a pigment. Evidence has been found of its use in paint pigment samples...

, and calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...

. Except for its vibrant green color, the properties of malachite are similar to those of azurite and aggregates of the two minerals occur frequently. Malachite is more common than azurite
Azurite
Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...

 and is typically associated with copper deposits around limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s, the source of the carbonate.

Large quantities of malachite have been mined in the Urals, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. It is found worldwide including in the Democratic Republic of Congo; Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...

; Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....

; Tsumeb
Tsumeb
Tsumeb is a city of 15,000 inhabitants and the largest town in Oshikoto region in northern Namibia. Tsumeb is the home of the world-famous Tsumeb mine, and the "gateway to the north" of Namibia. It is the closest town to the Etosha National Park...

, Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

; 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...

; Broken Hill, New South Wales
Broken Hill, New South Wales
-Geology:Broken Hill's massive orebody, which formed about 1,800 million years ago, has proved to be among the world's largest silver-lead-zinc mineral deposits. The orebody is shaped like a boomerang plunging into the earth at its ends and outcropping in the centre. The protruding tip of the...

; Lyon
Lyon
Lyon , is a city in east-central France in the Rhône-Alpes region, situated between Paris and Marseille. Lyon is located at from Paris, from Marseille, from Geneva, from Turin, and from Barcelona. The residents of the city are called Lyonnais....

, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

; and in the Southwestern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 notably in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

.

In Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

, malachite is extensively mined at Timna valley
Timna valley
The Timna Valley is located in southern Israel in the southwestern Arabah, approximately 30 km north of the Gulf of Aqaba and the town of Eilat...

, often called King Solomon's Mines
King Solomon's Mines
King Solomon's Mines is a popular novel by the Victorian adventure writer and fabulist Sir H. Rider Haggard. It tells of a search of an unexplored region of Africa by a group of adventurers led by Allan Quatermain for the missing brother of one of the party...

, although research has revealed an interruption in mining activity at the site during the 10th century BC, the time of the biblical Solomon. Archeological evidence indicates that the mineral has been mined and smelted at the site for over 3,000 years. Most of Timna's current production is also smelted, but the finest pieces are worked into silver jewelry.

See also

  • Aventurine
  • Azurite
    Azurite
    Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...

  • Brochantite
    Brochantite
    Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is CuSO4·3Cu2. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it is named for its discoverer, the French geologist and mineralogist, A. J. M...

  • Chrysocolla
    Chrysocolla
    Chrysocolla is a hydrated copper silicate mineral with formula 2H2Si2O54·nH2O.-Properties:Chrysocolla has a blue-green color and is a minor ore of copper, having a hardness of 2.5 to 3.5.-Name and discovery:...

  • Dioptase
    Dioptase
    Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is CuSiO3·H2O . It has a hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and...

  • Plancheite
    Plancheite
    Plancheite is a hydrated copper silicate mineral with the formula Cu8Si8O224•. It is closely related to shattuckite in structure and appearance, and the two minerals are often confused.-Structure:...


Further reading

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