Earth Sciences
Collections

Epidote and Hornblende

UNB-2016-0506Minerals » Silicates

Description

Sample of green granular Epidote with granular black Horblende that has a visible diamond cross section. Epidote (Ca2Al2FeOSiO4Si2O7(OH)) is a yellowish green to brownish black mineral. Lustre is vitreous and streak is colourless to grey. Hardness is 6 to 7 and cleavage is perfect in one direction lengthwise. Epidote usually occurs as long, slender prismatic crystals with grooves that are terminated by two faces. Epidote can also be thick tabular crystals, massive, columnar, acicular or can be granular. Hornblende ((Ca, Na, K)2-3(Mg, Fe2+, Fe3+, Al)5(Si, Al)8O22(OH)2) is a green, brown or black mineral. Lustre is submetallic, vitreous, pearly or silky and streak is colourless. Hardness is 5 to 6 cleavage is perfect in two directions forming a diamond shape. Hornblende usually occurs as short or long prismatic crystals with a diamond cross-section but can also be granular, columnar, fibrous or radiated.

Specifications

Object nameEpidote and Hornblende
IDUNB-2016-0506
Legal statusPermanent collection
CategoryMineral
Classification
Mineral group:
Silicates
Composition
  • Ca2(Al,Fe)3(SiO4)3(OH)
  • (Al,Fe2+,Fe3+Li,Mg,Mn,Ni)5−6(Al,Fe3+,Si)4(O,OH)18
  • K(Fe,Mg)3AlSi3O10(OH)2
  • BaTiSi3O9
  • (Mg,Fe)2Al3(Si5AlO18)
  • (Ca,Fe,Mg)3Al2BO3Si4O12(OH)
  • Be3Al2(Si6O18)
  • MgSiO3
  • (Mg,Fe2+)5Al(Si3Al)O10(OH)8
  • Na2Fe2+5[Si12O30]
  • (Na,Ca)Fe3+Si2O6
  • NaFe3+Si2O6
  • NaFe3+Si2O6
  • A0-1B2C5T8O22(OH,F,Cl)2
  • (Al,Fe)SiO4
  • Various (e.g., Muscovite - KAl2(AlSi3O10)(OH)2)
  • Al2Si2O5(OH)4
  • Be3Al2(Si6O18)
  • K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
  • NaAlSi2O6
  • Mg2Si2O6
  • Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
  • Na15Ca6(Fe2+,Mn2+)3Zr3Si25O733(CO3)
  • CaMgSi2O6
  • CaFeSi2O6
  • Ca2Al3(SiO4)3(OH)
  • CaSiO3
  • Ca2(Mg,Fe2+,Fe3+,Al)5(Si,Al)8O22(OH)2
  • (Ca,Na)19(Al,Mg,Fe)13(SiO4)10(Si2O7)4(OH,F,O)10
  • Na2AlSi3O8·H2O
  • Ca2(Mg5.0-4.5Fe2+0.0-0.5)Si8O22(OH)2
  • (Na,Ca)(Fe,Mg,Li,Al)3Al6(BO3)3(Si6O18)(OH)4
  • Ca2Al3(SiO4)3(OH)
  • LiAlSi2O6
  • MnSiO3
  • (Mn,Fe)SiO3
  • ADSi2O6
  • Ca2Al(AlSi3O10)(OH)2·H2O
  • (Ca,Na)(Mg,Fe)Si2O6
  • NaCa2Si3O8(OH)2H2O
  • LiAlSi4O10
  • NaAl2(AlSi3O10)(OH)2
  • Mg2Mg5Si8O22(OH)2
  • D3[Si2O5](OH)4
  • Mg3(Si2O5)(OH)4
  • Be₃Al₂(SiO₃)₆
  • A(D3)G6(T6O18)(BO3)3X3Z
  • (Mg,Al)8(Al,Si)6O20
  • SiO2 with variable amounts of water
  • KAl2(AlSi3O10)(F,OH)2
  • Al2(SiO4)O
OriginPutnam County, New York, U.S.A.
Pieces1
PartialNo
Measurements
  • 4cm x 8cm x 5.5cm

Map of Origin

Publications

  • Chesterman, C.W. 1979. Audubon Society, Field Guide to North American Rocks and Minerals. Knopf.