- Babingtonite
Infobox mineral
name = Babingtonite
category =
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caption = Babingtonite fromBaveno ,Piemonte ,Italy
formula = Ca2(Fe,Mn)FeSi5O14(OH)
molweight =
color = Dark green to black
habit = Prismatic crystals
system = Triclinic
twinning =
cleavage = Perfect on {001}, Good on {010} and {100}
fracture = Irregular/uneven
tenacity = Brittle
mohs = 5.5 to 6
luster = Vitreous
polish =
refractive = nα= 1.700 nβ= 1.710 nγ= 1.725
opticalprop =
birefringence = δ = 0.025
dispersion = r > v strong
pleochroism = Visible
fluorescence=
absorption =
streak =
gravity = 3.3
density =
melt =
fusibility =
diagnostic =
solubility =
diaphaneity = Translucent on thin edges, opaque
other =
references = [http://www.mindat.org/min-478.html Babingtonite at Mindat.org]Babingtonite is a
calcium iron manganese inosilicate mineral with the formula Ca2(Fe,Mn)FeSi5O14(OH). It is unusual in that iron(III) completely replaces the aluminium so typical of silicate minerals. It is a very dark green to black translucent (in thin crystals or splinters) mineral crystallizing in thetriclinic system with typically radial short prismatic clusters and druzy coatings. It occurs withzeolite minerals in cavities involcanic rock s. Babingtonite contains both iron(II) and iron(III) and shows weakmagnetism . It has aMohs hardness of 5.5 to 6 and aspecific gravity of 3.3.It was first described in 1824 from samples from
Arendal ,Aust-Agder ,Norway (which is its type locality) and was named after the Irishphysician andmineralogist William Babington (1757-1833).It is the official mineral (mineral emblem) of the Commonwealth of Massachusetts. [ [http://www.mass.gov/legis/laws/mgl/2-18.htm General Laws of Massachusetts, Part I. Administration of the Government, Title I. Jurisdiction and Emblems of the Commonwealth, The General Court, Statutes and Public Documents, Chapter 2. Arms, Great Seal and other Emblems of the Commonwealth, Chapter 2: Section 18. Mineral or mineral emblem of commonwealth] ]
References
* [http://www.mindat.org/min-478.html Mindat with location data]
* [http://webmineral.com/data/Babingtonite.shtml Webmineral]
* [http://mineral.galleries.com/minerals/silicate/babingto/babingto.htm Mineral galleries]
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