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Apophyllite and Stilbite

UNB-2020-0070Minerals » Silicates

Description

Original Description: *Incomplete. Apophyllite (KCa4Si8O20(F,OH) x 8H2O) can be colourless, white, grey, greenish, yellowish or reddish. Lustre is vitreous and pearly on the cleavage. Streak is white and hardness is 4 1/2 to 5. Cleavage is perfect in one direction. Apophyllite usually occurs as cube-like or tabular with a square cross-section. Apophyllite can also occur as lamellar, granular or compact. Stilbite (Na,Ca2Al5Si13O36 x 16H2O) can be white, greyish, yellowish, red or brown. Lustre is vitreous but pearly on the cleavage and streak is colourless. Hardness is 3 1/2 to 4 and cleavage is perfect in one direction. Stilbite usually occurs in bladed aggregates with numerous twinned crystals that are pinched in the middle and resembles wheat sheaves. Stilbite can also be radial, globular or tabular crystals (rare).

Specifications

Object nameApophyllite and Stilbite
IDUNB-2020-0070
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
OriginIndia
Pieces1
PartialNo

Map of Origin

Publications

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