Malachite

File:Great Orme Copper Mine - geograph.org.uk - 819.jpg malachite mine complex on the Great Orme, Wales]]

The stone's name derives (via {{langx|la|molochītis}}, {{langx|frm|melochite}}, and Middle English melochites) from Greek Μολοχίτης λίθος molochites lithos, "mallow-green stone", from μολόχη molochē, variant of μαλάχη malāchē, "mallow".[http://dictionary.reference.com/browse/Malachite Malachite], Dictionary.com The mineral was given this name due to its resemblance to the leaves of the mallow plant.{{OEtymD|malachite}} Copper (Cu²⁺) gives malachite its green color.{{Cite web |title=Minerals Colored by Metal Ions |url=http://minerals.gps.caltech.edu/color_causes/Metal_Ion/index.html |access-date=2023-03-01 |website=minerals.gps.caltech.edu}}

Malachite was mined from deposits near the Isthmus of Suez and the Sinai as early as 4000 BCE.{{cite journal |last1= Susarla |first1=S.M |date= 2016 |title= The colourful history of malachite green: from ancient Egypt to modern surgery |url= https://www.ijoms.com/article/S0901-5027(16)30250-8/fulltext |journal= International Journal of Oral and Maxillofacial Surgery|volume=46 |issue=3 |pages=401–403 |doi=10.1016/j.ijom.2016.09.022 |pmid=27771151}}

It was extensively mined at the Great Orme Mines in Britain 3,800 years ago, using stone and bone tools. Archaeological evidence indicates that mining activity ended {{circa|600 BCE}}, with up to 1,760 tonnes of copper being produced from the mined malachite.{{Cite web |url=http://www.historic-uk.com/HistoryUK/HistoryofWales/the-great-orme-mines/ |title=The Great Orme Mines |year=2014 |editor-last=Johnson |editor-first=Ben |access-date=2017-06-06}}{{Cite web |url=http://www.bbc.com/earth/story/20160420-the-ancient-copper-mines-dug-by-bronze-age-children |title=The Ancient Copper Mines Dug By Bronze Age Children |last=Ruggeri |first=Amanda |date=21 April 2016 |publisher=BBC |access-date=2017-06-06}}

Archaeological evidence indicates that the mineral has been mined and smelted to obtain copper at Timna Valley in Israel for more than 3,000 years.Parr, Peter J. (1974). "Review of 'Timma: Valley of the Biblical Copper Mines' by Beno Rothenberg Bulletin of the School of Oriental and African Studies, University of London, Vol. 37, No. 1, pp. 223–224 Since then, malachite has been used as both an ornamental stone and as a gemstone.

The use of azurite and malachite as copper ore indicators led indirectly to the name of the element nickel in the English language. Nickeline, a principal ore of nickel that is also known as niccolite, weathers at the surface into a green mineral (annabergite) that resembles malachite. This resemblance resulted in occasional attempts to smelt nickeline in the belief that it was copper ore, but such attempts always ended in failure due to high smelting temperatures needed to reduce nickel. In Germany this deceptive mineral came to be known as kupfernickel, literally "copper demon." The Swedish alchemist Baron Axel Fredrik Cronstedt (who had been trained by Georg Brandt, the discoverer of the nickel-like metal cobalt) realized that there was probably a new metal hiding within the kupfernickel ore, and in 1751 he succeeded in smelting kupfernickel to produce a previously unknown (except in certain meteorites) silvery white, iron-like metal. Logically, Cronstedt named his new metal after the nickel part of kupfernickel.

File:Outokumpu malachite.jpg's old mine.]]

Malachite often results from the supergene weathering and oxidation of primary sulfidic copper ores, and is often found with azurite (Cu₃(CO₃)₂(OH)₂), goethite, and calcite. 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 and is typically associated with copper deposits around limestones, the source of the carbonate.

Large quantities of malachite have been mined in the Urals, Russia. Ural malachite is not being mined {{asof|2006|lc=y}},[http://gazeta.aif.ru/_/online/aif/1334/46_02 Куда делись символы России?] {{Webarchive|url=https://web.archive.org/web/20131202231359/http://gazeta.aif.ru/_/online/aif/1334/46_02 |date=2013-12-02}} Argumenty i Fakty (24 May 2006) but G.N Vertushkova reports the possible discovery of new deposits of malachite in the Urals.Somin, L. M. [http://oldrushistory.ru/library/Tayny-sedogo-Urala/46 Тайны седого Урала. Малахит]. oldrushistory.ru It is found worldwide including in the Democratic Republic of the Congo; Gabon; Zambia; Tsumeb, Namibia; Mexico; Broken Hill, New South Wales; Burra, South Australia; Lyon, France; Timna Valley, Israel; and the Southwestern United States, most notably in Arizona.[http://www.mindat.org/show.php?id=2550&ld=1#themap Mindat map with over 8500 locations]. mindat.org

Anthropogenic malachite was historically believed to be the primary component of the patina which forms on copper and copper alloy structures exposed to open-air weathering; however, atmospheric sources of sulfate and chloride (such as air pollution or sea winds) typically favour the formation of brochantite or atacamite.{{cite journal|title=Basic copper carbonate and green patina|author=W. H. J. Vernon|journal=J. Chem. Soc.|year=1934|page=1853 |doi=10.1039/JR9340001853}} Malachite can also be produced synthetically, in which case it is referred to as basic copper carbonate or green verditer.

Malachite crystallizes in the monoclinic system. The structure consists of chains of alternating Cu²⁺ ions and OH⁻ ions, with a net positive charge, woven between isolated triangular CO₃²⁻ ions. Thus each copper ion is conjugated to two hydroxyl ions and two carbonate ions; each hydroxyl ion is conjugated with two copper ions; and each carbonate ion is conjugated with six copper ions.{{cite book |last1=Klein |first1=Cornelis |last2=Hurlbut |first2=Cornelius S. Jr. |title=Manual of mineralogy : (after James D. Dana) |date=1993 |publisher=Wiley |location=New York |isbn=047157452X |page=417 |edition=21st}}{{cite web |title=Malachite |url=http://rruff.geo.arizona.edu/AMS/result.php |website=American Mineralogical Crystal Structure Database |publisher=Department of Geology, University of Arizona |access-date=19 December 2020}}

File:Malachite 001.png|View along c axis of the crystal structure of malachite

File:Malachite 100.png|View along a axis of malachite crystal structure

File:Malachite 010.png|View along b axis of malachite crystal structure

File:Malachite-unit-cell-3D-bs-17.png|Unit cell of malachite

File:Malachite-formula-unit-and-coordination-fade-25-from-xtal-3D-bs-17-25.png|Formula unit and its coordination environment

File:Malachite-xtal-Cu1-coordination-3D-bs-N17-M25.png|Coordination environment of copper #1

File:Malachite-xtal-Cu2-coordination-3D-bs-N17-M25.png|Coordination environment of copper #2

File:Malachite-xtal-carbonate-coordination-3D-bs-N17-M25.png|Coordination environment of carbonate

File:Malachite-xtal-hydroxide-O4-coordination-3D-bs-N17-M25.png|Coordination environment of hydroxide #1

File:Malachite-xtal-hydroxide-O5-coordination-3D-bs-N17-M25.png|Coordination environment of hydroxide #2

File:Ajuar funerario de la Reina Roja - 8.jpg of Palenque is made from a mosaic of malachite.{{cite web |title=The Red Queen and Her Sisters: Women of Power in Golden Kingdoms|url=https://www.metmuseum.org/blogs/now-at-the-met/2018/golden-kingdoms-red-queen-women-of-power |website=www.metmuseum.org |access-date=13 October 2018}}]]

Malachite was used as a mineral pigment in green paints from antiquity until {{circa}} 1800.Gettens, R.J. and Fitzhugh, E. W. (1993) "Malachite and Green Verditer", pp. 183–202 in Artists’ Pigments. A Handbook of Their History and Characteristics, Vol. 2: A. Roy (Ed.) Oxford University Press. {{ISBN|0894682601}} The pigment is moderately lightfast, sensitive to acids, and varying in color. This natural form of green pigment has been replaced by its synthetic form, verditer, among other synthetic greens.

Malachite is also used for decorative purposes, such as in wands and the Malachite Room in the Hermitage Museum,{{Cite journal|last=Budrina|first=Ludmila|title=Малахитовые залы Петербурга, России, Европы... / Malachite salon of St.-Petersburg, Russia, Europe...|url=https://www.academia.edu/7717944|journal=// Блистательный Петербург. Роль архитекторов ХIХ века в создании неповторимого облика города. Материалы научно-практической конференции. Кафедра. Сб. науч. Ст. – СПб.: Государственный музей-памятник «Исаакиевский собор», 2011. – С. 23-49.|date=January 2011|language=en}} which features a huge malachite vase, and the Malachite Room in Castillo de Chapultepec in Mexico City.{{Cite journal|last=Budrina|first=Ludmila|title=La produzione in malachite dei Demidov: sulle trace degli oggetti alla prima esposizione universale / I Demidoff fra Russia e Italia. Gusto e prestigio di une famiglia in Europa dal XVIII al XX secolo. – P. 151-176, 9 tav.|url=https://www.academia.edu/7803720|journal=// I Demidoff Fra Russia e Italia. Gusto e Prestigio di Une Famiglia in Europa Dal XVIII al XX Secolo. A Cura di Lucia Tonini. Cultura e Memoria, Vol. 50. – Firenze: Leo S. Olschki, 2013.|date=January 2013|language=en}} Another example is the Demidov Vase, part of the former Demidov family collection, and now in the Metropolitan Museum of Art.[https://www.metmuseum.org/art/collection/search/199500 Monumental vase lapidary work: early 19th century; pedestal and mounts: 1819] Metropolitan Museum of Art. Retrieved 25 April 2021. "The Tazza", a large malachite vase, one of the largest pieces of malachite in North America and a gift from Tsar Nicholas II, stands as the focal point in the centre of the room of Linda Hall Library. In the time of Tsar Nicolas I decorative pieces with malachite were among the most popular diplomatic gifts.{{Cite book|last=Будрина|first=Людмила|title=Малахитовая дипломатия|publisher=Кабинетный ученый|year=2020|isbn=978-5-6044025-1-1|location=Екатеринбург|pages=208}} It was used in China as far back as the Eastern Zhou period.{{cite journal |last1=Langhals |first1=Heinz |last2=Bathelt |first2=Daniela |title=The Restoration of the Largest Archaelogical Discovery—a Chemical Problem: Conservation of the Polychromy of the Chinese Terracotta Army in Lintong |journal=Angewandte Chemie International Edition |date=1 December 2003 |volume=42 |issue=46 |pages=5676–5681 |doi=10.1002/anie.200301633|pmid=14661198}} The base of FIFA World Cup Trophy has two layers of malachite.

A 17th-century Spanish superstition held that having a child wear a lozenge of malachite would help them sleep, and keep evil spirits at bay.The Illustrated Book of Signs and Symbols by Miranda Bruce-Mitford, Dorling Kindersley Limited, London, 1996, p. 41 Marbodus recommended malachite as a talisman for young people because of its protective qualities and its ability to help with sleep.The Book of Talismans, Amulets and Zodiacal Gems, by William Thomas and Kate Pavitt, [1922], p. 254 It has also historically been worn for protection from lightning and contagious diseases and for health, success, and constancy in the affections. During the Middle Ages it was customary to wear it engraved with a figure or symbol of the Sun to maintain health and to avert depression to which Capricorns were considered vulnerable.

In ancient Egypt the colour green (wadj) was associated with death and the power of resurrection as well as new life and fertility. Ancient Egyptians believed that the afterlife contained an eternal paradise, referred to as the "Field of Malachite", which resembled their lives but with no pain or suffering.{{Cite web|url=http://www.ancientegyptonline.co.uk/colourgreen.html|title=Meaning of green in ancient Egypt|last=Hill|first=J|date=2010|website=Ancient Egypt Online|access-date=2016-11-28}}

File:Natural_copper_nugget.jpg

Simple methods of copper ore extraction from malachite involved thermodynamic processes such as smelting.{{Cite journal|last1=Johnson|first1=Cris E.|last2=Yee|first2=Gordon T.|last3=Eddleton|first3=Jeannine E.|date=2004-12-01|title=Copper Metal from Malachite circa 4000 B.C.E.|url=https://doi.org/10.1021/ed081p1777|journal=Journal of Chemical Education|volume=81|issue=12|pages=1777|doi=10.1021/ed081p1777|bibcode=2004JChEd..81.1777J|issn=0021-9584}} This reaction involves the addition of heat and a carbon, causing the carbonate to decompose leaving copper oxide and an additional carbon source such as coal converts the copper oxide into copper metal.{{Citation|last1=Day|first1=Jo|title=Reconstructing a Bronze Age Kiln from Priniatikos Pyrgos, Crete|date=2019-09-30|url=http://dx.doi.org/10.2307/j.ctvpmw4g8.11|work=Experimental Archaeology: Making, Understanding, Story-telling|pages=63–72|publisher=Archaeopress Publishing Ltd|isbn=978-1-78969-320-1|access-date=2021-02-25|last2=Kobik|first2=Maggie|doi=10.2307/j.ctvpmw4g8.11|s2cid=210629355}}

The basic word equation for this reaction is:

Copper carbonate + heat → carbon dioxide + copper oxide (color changes from green to black).

Copper oxide + carbon → carbon dioxide + copper (color change from black to copper colored).

Malachite is a low grade copper ore, however, due to increase demand for metals, more economic processing such as hydrometallurgical methods (using aqueous solutions such as sulfuric acid) are being used as malachite is readily soluble in dilute acids.{{Cite journal|last1=Ata|first1=O. N.|last2=Yalap|first2=H.|date=2007-06-01|title=Optimization of Copper Leaching from Ore Containing Malachite|url=https://doi.org/10.1179/cmq.2007.46.2.107|journal=Canadian Metallurgical Quarterly|volume=46|issue=2|pages=107–114|doi=10.1179/cmq.2007.46.2.107|bibcode=2007CaMQ...46..107A |s2cid=98163205|issn=0008-4433}}{{Cite web|title=Malachite|url=https://www.mindat.org/min-2550.html|access-date=2021-03-12|website=www.mindat.org}} Sulfuric acid is the most common leaching agent for copper oxide ores like malachite and eliminates the need for smelting processes.{{Cite journal|last1=Shabani|first1=M. A.|last2=Irannajad|first2=M.|last3=Azadmehr|first3=A. R.|date=2012-09-01|title=Investigation on leaching of malachite by citric acid|url=https://doi.org/10.1007/s12613-012-0628-9|journal=International Journal of Minerals, Metallurgy, and Materials|language=en|volume=19|issue=9|pages=782–786|doi=10.1007/s12613-012-0628-9|bibcode=2012IJMMM..19..782S|s2cid=96128268|issn=1869-103X}}

The chemical equation for sulfuric acid leaching of copper ore from malachite is as follows:

{{NumBlk|:

|{{overset|malachite|{{chem2|Cu2(OH)2CO3}}}} + {{overset|sulfuric acid|{{chem2|2H2SO4}}}} → {{overset|copper sulfate|{{chem2|2CuSO4}}}} + {{overset|carbon dioxide|{{chem2|CO2}}}} + {{overset|water|{{chem2|3H2O}}}}

|{{EquationRef|Reaction 1}}}}

Mining for malachite for ornamental or copper ore purposes involves open-pit mining or underground mining depending on the grade of the ore deposits.{{Cite web|title=Malachite|url=http://www.mine-engineer.com/mining/mineral/malachite.htm#:~:text=The%20distinctive%20bright-green%20hydrous,of%20other%20copper%20ore%20minerals.&text=Ores%20are%20removed%20either%20by%20open-pit%20or%20by%20underground%20mining.|access-date=2021-03-25|website=www.mine-engineer.com}} Open-pit and underground mining practices can cause environmental degradation through habitat and biodiversity loss.{{Cite journal|last1=Monjezi|first1=M.|last2=Shahriar|first2=K.|last3=Dehghani|first3=H.|last4=Samimi Namin|first4=F.|date=2009-07-01|title=Environmental impact assessment of open pit mining in Iran|url=https://doi.org/10.1007/s00254-008-1509-4|journal=Environmental Geology|language=en|volume=58|issue=1|pages=205–216|doi=10.1007/s00254-008-1509-4|bibcode=2009EnGeo..58..205M|s2cid=128616763|issn=1432-0495}}{{Cite journal|last=Salomons|first=W.|date=1995-01-01|title=Environmental impact of metals derived from mining activities: Processes, predictions, prevention|url=https://dx.doi.org/10.1016%2F0375-6742%2894%2900039-E|journal=Journal of Geochemical Exploration|series=Heavy Metal Aspects of Mining Pollution and Its Remediation|language=en|volume=52|issue=1|pages=5–23|doi=10.1016/0375-6742(94)00039-E|bibcode=1995JCExp..52....5S |issn=0375-6742}} Acid mine drainage can contaminate water and food sources to negatively impact human health if improperly managed or if leaks from tailing ponds occur.{{Cite web|title=Environmental Impact of Sulfuric Acid Leaching|url=http://www.savethesantacruzaquifer.info/Sulfuric%20Acid%20Impact.htm|access-date=2021-03-25|website=www.savethesantacruzaquifer.info}} The risk of health and environmental impacts of both traditional metallurgy and newer methods of hydrometallurgy are both significant, however, water conservation and waste management practices for hydrometallurgy processes for ore extraction, such as for malachite, are stricter and relatively more sustainable.{{Cite journal|last=Conard|first=Bruce R.|date=1992-06-01|title=The role of hydrometallurgy in achieving sustainable development|url=https://dx.doi.org/10.1016%2F0304-386X%2892%2990074-A|journal=Hydrometallurgy|series=Hydrometallurgy, Theory and Practice Proceedings of the Ernest Peters International Symposium. Part B|language=en|volume=30|issue=1|pages=1–28|doi=10.1016/0304-386X(92)90074-A|bibcode=1992HydMe..30....1C |issn=0304-386X}} New research is also being conducted on better alternatives to methods such as sulfuric acid leaching which has high environmental impacts, even under hydrometallurgy regulation standards and innovation. A common misconception about malachite is that, once wet, the crystal is immediately toxic to humans. However, simply getting the stone wet does not impact chemical structure to the degree of human contamination, as the copper is still within the lattice structure of the crystal.https://www.findgemstone.com/blog/is-malachite-toxic-when-wet/

File:Malachite-41365.jpg|Slice through a double stalactite, from Kolwezi, Democratic Republic of the Congo. Size 5.9 × 3.9 × 0.7 cm.

File:Azurite-Malachite-163967.jpg|Malachite and azurite from Bisbee, Warren District, Mule Mts, Cochise County, Arizona

File:Malachite-153552.jpg|Malachite stalactites (to 9 cm height), from Kasompi Mine, Katanga Province, Democratic Republic of the Congo. Size: 21.6×16.0×11.9 cm.

File:Malachite, da rep. dem. congo.JPG|Sample of malachite found at Kaluku Luku Mine, Lubumbashi, Shaba, Congo

File:Ermitáž (32).jpg|Vase in malachite in the Hermitage Museum, St Petersburg

File:Malachite, image taken under a stereoscopic microscope.jpg|Malachite, image taken under a stereoscopic microscope

File:Calendar (part of a set) MET DP-13486-011.jpg |British calendar, 1851, gilt bronze and malachite, height: 20.3 cm, Metropolitan Museum of Art (New York City)

File:Malachite at Kaleideum Children's Museum.jpg|Malachite at Kaleideum Children's Museum

File:Elephant in malachite Length 11 cm arp.jpg|Elephant carved from malachite. Length 11 cm.

File:Malachite-71023.jpg|A polished slice of malachite through three intergrown stalactites with bulls-eye banding

• Aventurine
• Brochantite
• Chrysocolla
• Dioptase
• Green pigments
• List of inorganic pigments
• Plancheite
• Pseudomalachite
• Turquoise
• Verdigris

{{Reflist}}

{{Wiktionary}}

{{Commons category}}

• [https://web.archive.org/web/20010417203442/http://www.hermitagemuseum.org/html_En/08/hm88_0_1_62.html Virtual tour of the Malachite Room]
• [http://colourlex.com/project/malachite/ Malachite], Colourlex
• [https://urfu.academia.edu/LudmilaBudrina/Malachite Malachite in art and malachite diplomacy]

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Category:Carbonate minerals

Category:Copper ores

Category:Gemstones

Category:Inorganic pigments

Category:Minerals in space group 14

Category:Monoclinic minerals