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Dioptase

UNB-2018-0009Minerals » Silicates » Cyclosilicates

Description

Sample of very small prismatic euhedral Dioptase crystals with a vitreous lustre. Average Dioptase crystal size: 0.1 cm x 0.1 cm x 0.1 cm. Dioptase (CuSiO2(OH)2) is an emerald-green mineral with a vitreous lustre that is slightly greasy on fracture. Streak is pale greenish-blue and hardness is 5. Cleavage is perfect in three directions. Dioptase usually occurs as short prismatic crystals capped by rhombohedrons but can also be granular or massive.

Specifications

Object nameDioptase
IDUNB-2018-0009
Legal statusPermanent collection
CategoryMineral
Classification
Mineral group:
Silicates
Sub-group:
Cyclosilicates
Composition
  • BaTiSi3O9
  • (Mg,Fe)2Al3(Si5AlO18)
  • (Ca,Fe,Mg)3Al2BO3Si4O12(OH)
  • Be3Al2(Si6O18)
  • Be3Al2(Si6O18)
  • Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
  • Na15Ca6(Fe2+,Mn2+)3Zr3Si25O733(CO3)
  • (Ca,Na)19(Al,Mg,Fe)13(SiO4)10(Si2O7)4(OH,F,O)10
  • (Na,Ca)(Fe,Mg,Li,Al)3Al6(BO3)3(Si6O18)(OH)4
  • Be₃Al₂(SiO₃)₆
  • A(D3)G6(T6O18)(BO3)3X3Z
OriginUnknown
Pieces1
PartialNo
Measurements
  • 1.6cm x 4.6cm x 4cm

Publications

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