linarite

{{Short description|Copper lead sulfate hydroxide mineral}}

{{Infobox mineral

| name = Linarite

| boxwidth =

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| image = Linarite-162465.jpg

| imagesize = 260px

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| category = Sulfate minerals

| formula = PbCu[(OH)₂|SO₄]

| IMAsymbol = Lna{{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 = 7.BC.65

| dana =

| system = Monoclinic

| class = Prismatic (2/m)
(same H-M symbol)

| symmetry = P2₁/m

| unit cell = a = 9.701(2), b = 5.65
c = 4.69 [Å]; β = 102.65°; Z = 2

| color = Deep azure blue

| colour =

| habit = Crystals elongated and tabular; in crusts and aggregates

| twinning = Common on {100}, also on {001}

| cleavage = Perfect on {100}, imperfect on {001}

| fracture = Conchoidal

| tenacity =

| mohs = 2.5

| luster = Sub-adamantine, vitreous

| streak = Pale blue

| diaphaneity = Transparent, translucent

| gravity = 5.3 – 5.5

| density =

| polish =

| opticalprop = Biaxial (−)

| refractive = n_α = 1.809 n_β = 1.838 n_γ = 1.859

| birefringence = δ = 0.050

| pleochroism = X = pale blue; Y = blue; Z = Prussian blue

| 2V = Measured: 80°

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| references = {{mindat|id=2403|title=Linarite|access-date=11 July 2022}}{{Cite web|last1=Barthelmy|first1=David|year=2014|url=http://www.webmineral.com/data/Linarite.shtml|access-date=27 June 2022|title = Linarite Mineral Data|website=Webmineral.com}}{{cite web |last1=Anthony |first1=John W. |last2=Bideaux |first2=Richard A. |last3=Bladh |first3=Kenneth W. |last4=Nichols |first4=Monte C. |title=Linarite |url=http://www.handbookofmineralogy.org/pdfs/linarite.pdf |website=Handbook of Mineralogy |publisher=Mineral Data Publishing |access-date=11 July 2022 |date=2005}}

}}

Linarite is a somewhat rare, crystalline mineral that is known among mineral collectors for its unusually intense, pure blue color. It is formed by the oxidation of galena and chalcopyrite and other copper sulfides. It is a combined copper lead sulfate hydroxide with formula PbCuSO₄(OH)₂.

Linarite occurs as monoclinic prismatic to tabular crystals and irregular masses. It is easily confused with azurite, but does not react with dilute hydrochloric acid as azurite does. It has a Mohs hardness of 2.5 and a specific gravity of 5.3 – 5.5.

Linarite was first identified in 1822. It is named after the Linares Plateau, Spain. It occurs in association with brochantite, anglesite, caledonite, leadhillite, cerussite, malachite and hemimorphite.