pyromorphite

{{Short description|Lead chlorophosphate mineral}}

{{Infobox mineral

| name = Pyromorphite

| category = Phosphate mineral
Apatite group

| boxwidth =

| image = Pyromorphite - Santa Eufemia, Cordoba, Spain.jpg

| imagesize = 260px

| caption =

| formula = Pb₅(PO₄)₃Cl

| IMAsymbol = Pym{{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}}

| molweight =

| strunz = 8.BN.05

| system = Hexagonal

| class = Dipyramidal (6/m)

(same H-M symbol)

| symmetry = P6₃/m

| color = Dark green to grass-green or green, yellow, yellow-orange, reddish orange, yellow-brown, greenish-yellow or yellowish-green, shades of brown, tan, grayish, white and may be colorless; colourless or faintly tinted in transmitted light.

| habit = Prismatic to acicular crystals, globular to reniform

| twinning = Rarely on {11{{overline|2}}2}

| cleavage = Imperfect- [10{{overline|1}}1]

| fracture = Uneven to sub-conchoidal

| tenacity = Brittle

| mohs = 3.5–4

| luster = Resinous to subadamantine

| polish =

| refractive = n_ω = 2.058 n_ε = 2.048

| opticalprop = Uniaxial (−) May be anomalously biaxial (−)

| birefringence = δ = 0.010

| dispersion =

| pleochroism = Weak

| fluorescence= May fluoresce yellow to orange under LW and SW UV

| absorption =

| streak = White

| gravity = 7.04 measured, 7.14 calculated

| density =

| melt =

| fusibility =

| diagnostic =

| solubility =

| diaphaneity = Transparent to translucent

| other = Piezoelectric if biaxial

| references = {{cite book| url = http://rruff.geo.arizona.edu/doclib/hom/pyromorphite.pdf | title = Handbook of Mineralogy}}{{cite web| url = http://webmineral.com/data/Pyromorphite.shtml | title = Pyromorphite | work = Webmineral data}}{{cite web| url = http://www.mindat.org/min-3320.html | title = Pyromorphite | work = Mindat.org}}

}}

Pyromorphite is a mineral species composed of lead chlorophosphate: Pb₅(PO₄)₃Cl, sometimes occurring in sufficient abundance to be mined as an ore of lead.{{cite book |url=https://books.google.com/books?id=pgn5w0JPWlMC&pg=PA216 |page=216 |title=Dana's Minerals and How to Study Them (After Edward Salisbury Dana) |author1=Cornelius S. Hurlbut |author2=W. Edwin Sharp |publisher=John Wiley & Sons |year=1998|isbn=978-0-471-15677-2 }} Crystals are common, and have the form of a hexagonal prism terminated by the basal planes, sometimes combined with narrow faces of a hexagonal pyramid.{{cite book |url=https://books.google.com/books?id=PAkpAQAAMAAJ |page=430 |title=Manual of Mineral Science |author1=Cornelis Klein |author2=Barbara Dutrow |publisher=Wiley |year=2007|isbn=978-0-471-72157-4 }} Crystals with a barrel-like curvature are not uncommon. Globular and reniform masses are also found.{{cite book |url=https://books.google.com/books?id=SnianWtB5WgC&pg=PA88 |page=88 |title=Cambridge Guide to Minerals, Rocks and Fossils |author1=A. Bishop |author2=A. Woolley |author3=W. Hamilton |publisher=Cambridge University Press |year=1999|isbn=978-0-521-77881-7 }} Pyromorphite is part of the apatite group of minerals and bears a close resemblance physically and chemically with two other minerals: mimetite (Pb₅(AsO₄)₃Cl) and vanadinite (Pb₅(VO₄)₃Cl).{{cite book |page=320 |url=https://books.google.com/books?id=P7vbXHR2mTYC&pg=PA320 |title=Pigment Compendium |author1=Nicholas Eastaugh |author2=Valentine Walsh |author3=Tracey Chaplin |author4=Ruth Siddall |publisher=Routledge |year=2008| isbn=978-1-136-37392-3 }} The resemblance in external characters is so close that, as a rule, it is only possible to distinguish between them by chemical tests. They were formerly confused under the names green lead ore and brown lead ore (German: Grünbleierz and Braunbleierz).{{cn|date=November 2024}}

The phosphate was first distinguished chemically by M. H. Klaproth in 1784,{{cite book| author = Klaproth | year = 1784 | url = https://books.google.com/books?id=lqU5AAAAcAAJ&pg=PA390 | title = Von dem Wassereisen, als einem mit Phosphorsäure verbundenen Eisenkalke | quote = On hydrosiderum [i.e., iron phosphide, Fe₂P] as a calcined [i.e., roasted] iron [that is] bonded with phosphoric acid), Chemische Annalen für die Freunde der Naturlehre …, 1 (5) : 390–399. From p. 394: After remarking that lead ores that contain phosphorus can be treated with strong acids to produce phosphoric acid, Klaproth notes that: " … wie solches zuerst Hr. Gahn in Schweden entdeckt, ich selbst aber bey Unersuchung des krystallisirten grünen Bleyerzes von der heil. Dreyfaltigkeit zu Zschopau bestätigt gefunden habe." ( … as such Mr. Gahn in Sweden first discovered, I myself, however, have found [to be] confirmed by investigation of the crystallized green lead ore [i.e., pyromorphite] from the Holy Trinity at Zschopau in Germany] | language = de}}Details of Klaproth's chemical analysis of pyromorphite appear in: Klaproth (1785) [https://books.google.com/books?id=NYjBkHlP7CIC&pg=RA1-PA13 "Ueber die Phosphorsäure im Zschopauer grünen Bleyspathe"] (On phosphoric acid in green lead spar from Zschopau), Beyträge zu den chemischen Annalen, 1 (1) : 13–21.{{cite book | url = https://books.google.com/books?id=8A8KAAAAIAAJ&pg=PA146 | title = LXXXVII. Chemische Untersuchung der phosphorsauren Bleierze: I. Zeisiggrünes Bleierz von Zschopau. (87. Chemical investigation of the lead ores [containing] phosphoric acid: I. Siskin-green lead ore from Zschopau) in: Klaproth, Martin Heinrich, Beiträge zur chemischen Kenntnis der Mineralkörper [Contributions to our chemical knowledge of minerals] | location = Posen, (Germany): Decker und Co.; Berlin, Germany | publisher = Heinrich August Rottmann | year = 1802 | volume = 3 | pages = 146–153}}{{cite web | url = http://tw.strahlen.org/typloc/pyromorphit.html | title= Entdeckung von Pyromorphit (Discovery of pyromorphite) | author = Dr. Thomas Witzke | language = de}} and it was named pyromorphite by J. F. L. Hausmann in 1813.{{cite book | last = Hausmann | first = Johann Friedrich Ludwig | title= Handbuch der Mineralogie | location = Göttingen, Germany | publisher = Vandenhoeck und Ruprecht | year = 1813 | url = https://babel.hathitrust.org/cgi/pt?id=nyp.33433062733062;view=1up;seq=1114 | pages = 1090–1093}}{{cite book | last = Chester | first = Albert Huntington | title = A Dictionary of the Names of Minerals Including Their History and Etymology | location =New York, New York | publisher = John Wiley & Sons | year =1896 | url = https://books.google.com/books?id=IiwFAAAAMAAJ&pg=PA224 | page = 224}} The name is derived from the Greek for pyr (fire) and morfe'' (form) due to its crystallization behavior after being melted.

Paecilomyces javanicus is a mold collected from a lead-polluted soil that is able to form biominerals of pyromorphite.{{cite journal | title = Fungal transformation of metallic lead to pyromorphite in liquid medium | journal = Chemosphere | volume = 113 | date = October 2014 | pages = 17–21| doi = 10.1016/j.chemosphere.2014.03.085 | pmid = 25065784 | bibcode = 2014Chmsp.113...17R |last1= Rhee |first1= Young Joon |last2= Hillier |first2= Stephen |last3= Pendlowskic |first3= Helen |last4= Gadd|first4= Geoffrey Michael|authorlink4=Geoffrey Michael Gadd|url=https://www.sciencedirect.com/science/article/abs/pii/S0045653514004421 |access-date=2024-11-12|url-access=subscription}}