Editing Augite (section)

{{Short description|Common rock-forming pyroxene mineral}}
{{Infobox mineral
| name        = Augite
| category    = [[Inosilicates]]
| image       = Augite Rwanda.jpg
| imagesize   = 260px
| alt         = 
| caption     = Augite – [[Mount Muhabura|Muhavura volcano]]
| formula     = {{chem2|(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6}}
|IMAsymbol=Aug<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      = 9.DA.15
| system      = [[Monoclinic]]
| class       = Prismatic (2/m) <br /><small>(same [[H-M symbol]])</small>
| symmetry    = ''C2/c''
| unit cell   = a = 9.699, b = 8.844 <br />c = 5.272&nbsp;[Å] <br />β = 106.97°; Z&nbsp;=&nbsp;4
| color       = Black, brown, greenish, violet-brown; in thin section, colorless to gray with zoning common
| habit       = Commonly as stubby prismatic crystals, also acicular, skeletal, dendritic
| twinning    = Simple or multiple on {100} and {001}
| cleavage    = {110} good with 87° between {110} and {1{{overline|1}}0}; parting on {100} and {010}
| fracture    = uneven to conchoidal
| tenacity    = brittle
| mohs        = 5.5 to 6
| luster      = Vitreous, resinous to dull
| refractive  = n<sub>α</sub> = 1.680–1.735, n<sub>β</sub> = 1.684–1.741, n<sub>γ</sub> = 1.706–1.774
| opticalprop = Biaxial (+)
| birefringence = δ = 0.026–0.039
| pleochroism = X = pale green, pale brown, green, greenish yellow; Y = pale brown, pale yellow-green, violet; Z = pale green, grayish green, violet
| streak      = Greenish-white
| gravity     = 3.19–3.56
| density     =
| melt        =
| fusibility  =
| diagnostic  =
| solubility  =
| diaphaneity = Transparent to opaque
| other       =
| references  = <ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/augite.pdf Handbook of Mineralogy]</ref><ref name=Mindat>[http://www.mindat.org/min-419.html Augite on Mindat.org]</ref><ref name=Webmin>[http://webmineral.com/data/Augite.shtml Webmineral data for Augite]</ref>
}}

'''Augite''', also known as '''Augurite''', is a common rock-forming  [[pyroxene]] [[mineral]] with formula {{chem2|(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6}}. The [[crystal]]s are [[monoclinic]] and [[prismatic]]. Augite has two prominent cleavages, meeting at angles near 90 degrees.