{{short description|Natural mineral form of lead sulfide}} {{other uses}} {{Infobox mineral | name = Galena | category = Sulfide mineral | image = Galena - Huallanca, Bologesi, Ancash, Peru.jpg | imagesize = 275px | caption = Galena with minor pyrite | formula = PbS | IMAsymbol = Gn<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref> | molweight = | strunz = 2.CD.10 | dana = 2.8.1.1 | system = Cubic | class = Hexoctahedral (m{{overline|3}}m) <br/>H–M symbol: ({{sfrac|4|m}} {{overline|3}} {{sfrac|2|m}}) | symmetry = ''Fm''{{overline|3}}m | unit cell = ''a'' = 5.936 Å; ''Z'' = 4 | color = Lead gray and silvery | habit = Cubes and octahedra, blocky, tabular and sometimes skeletal crystals | twinning = Contact, penetration and lamellar | cleavage = Cubic perfect on {001}, parting on {111} | fracture = Subconchoidal | tenacity = Brittle | mohs = 2.5–2.75 | luster = Metallic on cleavage planes | refractive = | opticalprop = Isotropic and opaque | birefringence = | pleochroism = | streak = Lead gray | gravity = 7.2–7.6 | density = | melt = | fusibility = 2 | diagnostic = | solubility = | diaphaneity = Opaque | other = Natural semiconductor | references = <ref name=HBM>{{cite book|editor1-last=Anthony |editor1-first=John W. |editor2-last=Bideaux |editor2-first=Richard A. |editor3-last=Bladh |editor3-first=Kenneth W. |editor4-last=Nichols |editor4-first=Monte C. |title= Handbook of Mineralogy|publisher= Mineralogical Society of America|place= Chantilly, VA|url=http://rruff.geo.arizona.edu/doclib/hom/galena.pdf|chapter=Galena |isbn=0962209708 |volume=1 |year=1990}}</ref><ref name=Webmineral>{{cite web |url= http://www.webmineral.com/data/Galena.shtml |title= Galena |publisher= Webmineral}}</ref><ref name=Mindat>[http://www.mindat.org/min-1641.html Galena]. Mindat.org</ref> }} '''Galena''', also called '''lead glance''', is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.<ref name=":0">{{Cite book| publisher = SME| isbn = 9780873352666| last1 = Young| first1 = Courtney A.|first2=Patrick R.|last2= Taylor |first3=Corby G.|last3= Anderson| title = Hydrometallurgy 2008: Proceedings of the Sixth International Symposium| date = 2008}}</ref>
Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms. It is often associated with the minerals sphalerite, calcite and fluorite.
As a pure specimen held in the hand, under standard temperature and pressure, galena is insoluble in water and so is almost non-toxic. Handling galena under these specific conditions (such as in a museum or as part of geology instruction) poses practically no risk; however, as lead(II) sulfide is reasonably reactive in a variety of environments, it can be highly toxic if swallowed or inhaled, particularly under prolonged or repeated exposure.<ref name="q370">{{cite web | title=Lead Sulfide SDS (Safety Data Sheet) | website=Flinn Scientific | date=2014-03-25 | url=https://www.flinnsci.com/sds_442-lead-sulfide/sds_442/?srsltid=AfmBOopzodmbVtFbF4l401tsO9y5smPXHCGjhujrEyazqReW5g4uUPWl | access-date=2025-03-07}}</ref>
==Occurrence== [[File:Baryte-Galena-Pyrite-203072.jpg|thumb|left|alt=Galena with baryte and pyrite|Galena with baryte and pyrite from Cerro de Pasco, Peru; {{convert|5.8|×|4.8|×|4.4|cm|in|abbr=on}}]] Galena is the main ore of lead, used since ancient times,<ref name=Lucas >{{cite journal |last1=Lucas |first1=A. |title=Silver in Ancient Times |journal=The Journal of Egyptian Archaeology |date=May 1928 |volume=14 |issue=1 |pages=313–319 |doi=10.1177/030751332801400160|s2cid=192277012 }}</ref> since lead can be smelted from galena in an ordinary wood fire.<ref>{{cite journal |last=Winder |first=C. |title=The history of lead – Part 3 |year=1993b |url=http://lead.org.au/lanv2n3/lanv2n3-22.html |access-date=12 February 2016 |url-status=dead |archive-url=https://web.archive.org/web/20070831200744/http://lead.org.au/lanv2n3/lanv2n3-22.html |archive-date=31 August 2007 |journal=LEAD Action News |volume=2 |issue=3 |issn=1324-6011 }}</ref> Galena typically is found in hydrothermal veins in association with sphalerite, marcasite, chalcopyrite, cerussite, anglesite, dolomite, calcite, quartz, barite, and fluorite. It is also found in association with sphalerite in low-temperature lead-zinc deposits within limestone beds. Minor amounts are found in contact metamorphic zones, in pegmatites, and disseminated in sedimentary rock.<ref name=Klein>{{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 |edition=21st |pages=354–356}}</ref>
{{anchor|Argentiferous galena}} In some deposits, the galena contains up to 0.5% silver, a byproduct that far surpasses the main lead ore in revenue.<ref name="Hobart">{{Cite web |title=Galena Mineral {{!}} Uses and Properties |author=Hobart M. King |work=geology.com |date= |access-date=29 March 2024 |url= https://geology.com/minerals/galena.shtml}}</ref> In these deposits significant amounts of silver occur as included silver sulfide mineral phases or as limited silver in solid solution within the galena structure. These '''argentiferous galenas''' have long been an important ore of silver.<ref name=Lucas/><ref>{{cite journal|doi=10.11141/ia.56.9|title=Sending Laurion Back to the Future: Bronze Age Silver and the Source of Confusion|last1=Wood|first1=J. R.|last2=Hsu|first2=Y-T.|last3=Bell|first3=C.|journal=Internet Archaeology|year=2021|volume=56|issue=9|s2cid=236973111|doi-access=free}}</ref> Silver-bearing galena is almost entirely of hydrothermal origin; galena in lead-zinc deposits contains little silver.<ref name=Klein/>
Galena deposits are found worldwide in various environments.<ref name=Mindat/> Noted deposits include those at Freiberg in Saxony;<ref name=HBM/> Cornwall, the Mendips in Somerset, Derbyshire, and Cumberland in England; the Linares mines in Spain were worked from before the Roman times until the end of the 20th century;<ref>{{Cite book |last=Calvo |first=Miguel |title=Minerales y Minas de España. Vol. II. Sulfuros y sulfosales. |publisher=Museo de Ciencias Naturales de Alava |year=2003 |isbn=84-7821-543-3 |location=Spain |pages=293–301 |language=es |trans-title=Minerals and mines of Spain}}</ref> the Madan and Rhodope Mountains in Bulgaria; the Sullivan Mine of British Columbia; Broken Hill and Mount Isa in Australia; and the ancient mines of Sardinia.
In the United States, it occurs most notably as lead-zinc ore in the Mississippi Valley type deposits of the Lead Belt in southeastern Missouri, which is the largest known deposit,<ref name=HBM/> and in the Driftless Area of Illinois, Iowa and Wisconsin, providing the origin of the name of Galena, Illinois, a historical settlement known for the material. Galena also was a major mineral of the zinc-lead mines of the tri-state district around Joplin in southwestern Missouri and the adjoining areas of Kansas and Oklahoma.<ref name=HBM/> Galena is also an important ore mineral in the silver mining regions of Colorado, Idaho, Utah and Montana. Of the latter, the Coeur d'Alene district of northern Idaho was most prominent.<ref name=HBM/>
Australia is the world's leading producer of lead as of 2021, most of which is extracted as galena. Argentiferous galena was accidentally discovered at Glen Osmond in 1841, and additional deposits were discovered near Broken Hill in 1876 and at Mount Isa in 1923.<ref>{{cite web |title=Lead |url=https://www.ga.gov.au/education/classroom-resources/minerals-energy/australian-mineral-facts/lead |website=Geoscience Australia |date=4 March 2018 |publisher=Australian Government |access-date=26 June 2021}}</ref> Most galena in Australia is found in hydrothermal deposits emplaced around 1680 million years ago, which have since been heavily metamorphosed.<ref>{{cite journal |last1=Walters |first1=Stephen |last2=Bailey |first2=Andrew |title=Geology and mineralization of the Cannington Ag-Pb-Zn deposit; an example of Broken Hill-type mineralization in the eastern succession, Mount Isa Inlier, Australia |journal=Economic Geology |date=1998-12-01 |volume=93 |issue=8 |pages=1307–1329 |doi=10.2113/gsecongeo.93.8.1307|bibcode=1998EcGeo..93.1307W }}</ref>
The largest documented crystal of galena is composite cubo-octahedra from the Great Laxey Mine, Isle of Man, measuring {{convert|25|×|25|×|25|cm|in|0|abbr=on}}.<ref>{{cite journal| url = http://www.minsocam.org/ammin/AM66/AM66_885.pdf| journal = American Mineralogist| volume = 66| pages = 885–907| year= 1981| title= The largest crystals| last= Rickwood |first= P. C.}}</ref> This specimen is on permanent display in the minerals gallery of the Natural History Museum, London.
==Importance==
[[File:Galena Sweetwater Minéraux SU.jpg|thumb|Galena from Sweetwater, Missouri, USA (Sorbonne University).]]
Galena is the official state mineral of the U.S. states of Kansas,<ref>{{Citation |title = Official state mineral |chapter= 2018 Statute Chapter 73 Article 38 |publisher= Kansas Legislature |chapter-url= http://www.kslegislature.org/li/b2019_20/statute/073_000_0000_chapter/073_038_0000_article/073_038_0001_section/073_038_0001_k/ |access-date= 2019-12-05}}</ref> Missouri,<ref>{{cite web |url=http://www.sos.mo.gov/symbols/ |title=Office of the Secretary of State, Missouri – State Symbols |access-date=2009-11-12 |publisher=State of Missouri}}</ref> and Wisconsin;<ref>{{cite web|url=http://www.wisconsin.gov/state/core/wisconsin_state_symbols.html |title=Wisconsin State Symbols |access-date=2009-11-12 |publisher=State of Wisconsin |url-status=dead |archive-url=https://web.archive.org/web/20100112222837/http://www.wisconsin.gov/state/core/wisconsin_state_symbols.html |archive-date=2010-01-12 }}</ref> the former mining communities of Galena, Kansas,<ref>Rydjord, John (1972) ''Kansas Place-Names'', University of Oklahoma Press. p. 77 {{ISBN|0-8061-0994-7}}</ref><ref>{{cite book | url=https://books.google.com/books?id=9V1IAAAAMAAJ&pg=PA133 | title=The Origin of Certain Place Names in the United States | publisher=Govt. Print. Off. | author=Gannett, Henry | year=1905 | pages=133}}</ref> Galena, Illinois,<ref name=GalenaFacts>{{cite web|author=Galena Historical Society|date=June 21, 2006|title=History Highlights|access-date=April 13, 2007|url=http://galenahistorymuseum.org}}</ref> Galena, South Dakota and Galena, Alaska,<ref name="dec">[http://www.dec.state.ak.us/SPAR/CSP/sites/galena.htm state.ak.us]</ref> take their names from deposits of this mineral.
==Structure== Galena belongs to the octahedral sulfide group of minerals that have metal ions in octahedral positions, such as the iron sulfide pyrrhotite and the nickel arsenide niccolite. The galena group is named after its most common member, with other isometric members that include manganese bearing alabandite and niningerite.<ref name=Klein/><ref name=Mindat/>
Divalent lead (Pb) cations and sulfur (S) anions form a close-packed cubic unit cell much like the mineral halite of the halide mineral group. Zinc, cadmium, iron, copper, antimony, arsenic, bismuth and selenium also occur in variable amounts in galena. Selenium substitutes for sulfur in the structure constituting a solid solution series. The lead telluride mineral altaite has the same crystal structure as galena.<ref name=Klein/>
==Geochemistry==
Within the weathering or oxidation zone galena alters to anglesite (lead sulfate) or cerussite (lead carbonate).<ref name=Klein/> Galena exposed to acid mine drainage can be oxidized to anglesite by naturally occurring bacteria and archaea, in a process similar to bioleaching.<ref>{{cite journal|doi=10.1016/j.hydromet.2004.07.001|title=Kinetics and mechanism of the bacterial and ferric sulphate oxidation of galena|year=2004|last1=Da Silva|first1=Gabriel|journal=Hydrometallurgy|volume=75|issue=1–4|pages=99–110|bibcode=2004HydMe..75...99D }}</ref>
==Uses== [[File:CatWhisker.jpg|thumb|left|Galena cat's whisker detector]]
One of the oldest uses of galena was to produce kohl, an eye cosmetic now regarded as toxic due to the risk of lead poisoning.<ref>{{Cite web |title=Toxic trends |author= |work=Wellcome Collection |date= 17 December 2019|access-date=29 March 2024 |url= https://wellcomecollection.org/articles/XefkNBEAAPuo1KaD}}</ref> In Ancient Egypt, this was applied around the eyes to reduce the glare of the desert sun and to repel flies, which were a potential source of disease.<ref>{{cite book|author=Metropolitan Museum of Art |title=The Art of Medicine in Ancient Egypt |location=New York |date=2005 |page=10 |isbn=1-58839-170-1}}</ref>
In pre-Columbian North America, galena was used by indigenous peoples as an ingredient in decorative paints and cosmetics, and widely traded throughout the eastern United States.<ref name=IUPUI>{{cite news |title=Lead pollution from Native Americans attributed to crushing galena for glitter paint, adornments |publisher=Indiana University–Purdue University Indianapolis |date=21 October 2019 |url=https://news.iu.edu/stories/2019/10/iupui/releases/21-native-american-kincaid-mounds-pre-columbian-period-galena.html |access-date=11 January 2020}}</ref> Traces of galena are frequently found at the Mississippian city at Kincaid Mounds in present-day Illinois.<ref>[https://www.atlasobscura.com/articles/found-precolumbian-glitter-in-illinois The Glittery Legacy of Lead at a Historic Native American Site], Atlas Obscura, November 7, 2019</ref> The galena used at the site originated from deposits in southeastern and central Missouri and the Upper Mississippi Valley.<ref name=IUPUI />
Galena is the primary ore of lead, and is often mined for its silver content.<ref name=Lucas /> It is used as a source of lead in ceramic glaze.<ref>[http://www.thepotteries.org/types/glaze.htm Glaze]. thepotteries.org</ref>
Galena is a semiconductor with a small band gap of about 0.4 eV, which found use in early wireless communication systems. It was used as the crystal in crystal radio receivers, in which it was used as a point-contact diode capable of rectifying alternating current to detect the radio signals. The galena crystal was used with a sharp wire, known as a "cat's whisker", in contact with it.<ref name="Lee2007">{{Cite FTP |last1=Lee|first1=Thomas H.|title=The (Pre-)History of the Integrated Circuit: A Random Walk|volume=12|issue=2|year=2007|pages=16–22|issn=1098-4232|doi=10.1109/N-SSC.2007.4785573|s2cid=17583856|server=IEEE Solid-State Circuits Newsletter|url-status=dead|url=ftp://119.235.48.163/BIET/Materials/Journals/ECE/Solid-State_Circuits_Newslette/The_Pre-_History_of_the_Integrated_Circuit_A_Random_Walk-C9G.pdf}}</ref>
In modern times, galena is primarily used to extract its constituent minerals. In addition to silver, it is the most important source of lead, for uses such as in lead-acid batteries.<ref name="Hobart"/>
==See also== *List of minerals *Lead smelter
==References== {{reflist|30em}}
==External links== {{Commons category}} * [https://web.archive.org/web/20090605154039/http://www.atsdr.cdc.gov/HEC/CSEM/lead/ Case Studies in Environmental Medicine (CSEM): Lead Toxicity.] * [https://www.atsdr.cdc.gov/toxfaqs/tfacts13.pdf ToxFAQs: Lead.] * [https://web.archive.org/web/20070415151632/http://www.mii.org/Minerals/photolead.html Mineral Information Institute] entry for lead.
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Category:Lead minerals Category:Galena group Category:Alchemical substances Category:Cubic minerals Category:Glances Category:Minerals in space group 225 Category:History of radio technology Category:Culture of Wisconsin Category:Symbols of Wisconsin Category:Symbols of Missouri