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Cactus Quartz (Witch's finger)

UNB-2017-0245Minerals » Tectosilicates

Description

White secondary growth of Quartz crystals that are granular in appearance and have a vitreous lustre. Quartz (SiO2) can have a variety of colours from white to purple. Lustre can be greasy or vitreous and streak is white. Hardness is 7. Quartz usually occurs as long or short prismatic crystals that are terminated by double rhombohedrons and have striations crosswise. Quartz can also be massive, granular or disseminated. Cactus Quartz is a second generation of Quartz crystals that grew on the primary generation.

Specifications

Object nameCactus Quartz (Witch's finger)
IDUNB-2017-0245
Legal statusPermanent collection
CategoryMineral
Classification
Mineral group:
Tectosilicates
Composition
  • CaB2Si2O8(OH,F)2
  • (Ca,Na2,K2)Al2Si4O12•6H2O
  • (Ca,Na)AlSi2O8
  • (Na2,K2)Al2Si4O12•2H2O
  • (Na,Ca)4(Al,Na)3Si9O24(Cl,CO3)2
  • (MAlO2)(SiO 2)x(H2O)y
  • (Na,K)AlSiO4
  • Na2Al2Si3O10·2H2O
  • KAlSi3O8
  • Na2Ca2Al6Si9O30·8H2O
  • K(AlSi2O6)
  • CaAl2Si4O12·4H2O
  • Pectolite NaCa2Si3O8(OH)2H2O with trace amounts of copper
  • (Ca,Na)(Al,Si)4O8
  • SiO2 with water inclusion
  • (Na,Ca)4-8Al6Si6(O,S)24(Cl,SO4)1-2
  • Na8(Al6Si6O24)Cl2
  • CaAl2Si3O10·3H2O
  • SiO2
  • (Cs,Na)2Al2Si4O12·2H2O
  • (Na, Ca)(Al, Si)AlSi2O8
  • KAlSi3O8
  • (Na,K)AlSi3O8
  • (Na,K)AlSi3O8
  • CaAl2Si2O8
  • SiO2
OriginUnknown
Pieces1
PartialNo
Measurements
  • 9.9cm x 1.5cm x 1.2cm

Publications

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