Clinozoisite

{{Infobox mineral

| name = Clinozoisite

| image = Clinozoisite, Amphibole Group - Mount Belvidere Quarries, Vermont, USA.jpg

| imagesize = 260px

| alt =

| caption = Clinozoisite

| category = Sorosilicates
Epidote group

| formula = Ca₂Al₃(Si₂O₇)(SiO₄)O(OH)

| IMAsymbol=Czo{{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}}

| strunz = 9.BG.05a

| dana = 58.2.1a.4

| system = Monoclinic

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

| symmetry = P2₁/m

| unit cell = a = 8.879, b = 5.583
c = 10.155 [Å]; β = 115.50°; Z = 2

| color = Colorless, green, gray, light green, yellow green, pink

| habit = Elongated primatic crystals, striated; granular to fibrous

| twinning = Lamellar on {100} uncommon

| cleavage = Perfect on {001}

| fracture = Irregular/uneven

| tenacity = Brittle

| mohs = 6–7

| luster = Vitreous

| streak = Grayish white

| diaphaneity = Transparent to translucent

| gravity = 3.3–3.4

| density =

| polish =

| opticalprop = Biaxial (+)

| refractive = n_α = 1.706 – 1.724 n_β = 1.708 – 1.729 n_γ = 1.712 – 1.735

| birefringence = δ = 0.006 – 0.011

| pleochroism =

| 2V = 14 to 90° measured

| dispersion =

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| references = [http://www.mindat.org/min-1087.html Clinozoisite] on Mindat.org{{Cite web |url=http://www.handbookofmineralogy.com/pdfs/clinozoisite.pdf |title=Clinozoisite in the Handbook of Mineralogy |access-date=2014-03-24 |archive-date=2015-09-24 |archive-url=https://web.archive.org/web/20150924052813/http://www.handbookofmineralogy.com/pdfs/clinozoisite.pdf |url-status=dead }}[http://webmineral.com/data/Clinozoisite.shtml Clinozoisite data on Webmineral]

}}

Clinozoisite is a complex calcium aluminium sorosilicate mineral with formula: Ca₂Al₃(Si₂O₇)(SiO₄)O(OH). It forms a continuous solid solution series with epidote by substitution of iron(III) in the aluminium (m3 site) and is also called aluminium epidote.

Clinothulite is a manganese bearing variety with a pinkish hue due to substitution of Mn(III) in the aluminium site.[http://www.mindat.org/min-27132.html Clinothulite on Mindat]

It was originally discovered in 1896 in East Tyrol, Austria, and is so-named because of its resemblance to zoisite and its monoclinic crystal structure.

It occurs in rocks which have undergone low to medium grade regional metamorphism and in contact metamorphism of high calcium sedimentary rocks. It also occurs in saussurite alteration of plagioclase.

Jadeite bearing pyroxene minerals have suggested clinozoisite and paragonite are associated and derived from lawsonite releasing quartz and water via the following reaction:{{Cite book |title= Single-chain Silicates, Volume 2A |last= Deer |first= William A. |year= 1997 |publisher= Geological Society of London|page= 477}}

4CaAl2Si2O8(H2O)2 + NaAlSi2O6 <=> 2Ca2Al3Si3O12(OH) + NaAl3Si3O10(OH)2 + SiO2 + 6H2O