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Apophyllite and Stillbite

UNB-2017-0097Minerals » Silicates

Description

Sample is greenish euhedral tabular Apophylite (4.5 cm in size for the largest crystal) with a vitreous lustre that is entwined with red Stilbite that resembles "wheat sheaves". Apophyllite (KCa4Si8O20(F,OH) x 8H2O) can be colourless, white, grey, greenish, yellowish or reddish in colour. Lustre is vitreous and can be pearly on cleavage planes. Streak is white and hardness is 4 1/2 to 5. Apophyllite is usually cube-like or tabular but can also be lamellar, granular or compact in form. Stillbite (NaCa2Al5Si13O36 x 16H2O) can be white, greyish, yellowish, red or brown with a vitreous lustre that is pearly on the cleavage plane. Streak is colourless and hardness is 3 1/2 to 4. Cleavage is perfect in one direction. Stilbite is usually bladed aggregates that resembles as "wheat sheaves". *Smallman Collection.

Specifications

Object nameApophyllite and Stillbite
IDUNB-2017-0097
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
OriginMaharashtra, India
Pieces1
PartialNo
Measurements
  • 9cm x 8cm x 3.5cm

Map of Origin

Publications

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