Zincite

(repeating unit)(Zn,Mn)OIMA symbolZnc^[1]Strunz classification4.AB.20Dana classification04.02.02.01Crystal systemHexagonalCrystal classDihexagonal pyramidal (6mm)
H-M symbol: (6mm)Space groupP6₃mcIdentificationColorOrange, yellow-orange to deep red, red, rarely yellow, rarely green and colorless to whiteCrystal habitDisseminated – occurs in small, distinct particles dispersed in matrix.TwinningOn {0001}CleavageOn {1010}, perfect; parting on {0001}FractureConchoidalTenacityBrittleMohs scale hardness4LusterSubadamantine to resinousStreakYellowish orangeDiaphaneityTranslucent, transparent in thin fragmentsSpecific gravity5.64–5.68Optical propertiesUniaxial (+)Refractive indexn_ω = 2.013, n_ε = 2.029Birefringenceδ = 0.016References^[2][3]

Zincite is the mineral form of zinc oxide (ZnO). Its crystal form is rare in nature; a notable exception to this is at the Franklin and Sterling Hill Mines in New Jersey, an area also famed for its many fluorescent minerals. It has a hexagonal crystal structure and a color that depends on the presence of impurities. The zincite found at the Franklin Furnace is red-colored, mostly due to iron and manganese dopants, and associated with willemite and franklinite.

Zincite crystals can be grown artificially, and synthetic zincite crystals are available as a by-product of zinc smelting. Synthetic crystals can be colorless or can range in color from dark red, orange, or yellow to light green.

Both natural and synthetic zincite crystals are significant for their early use as semiconductor crystal detectors in the early development of crystal radios before the advent of vacuum tubes. As an early radio detector it was used in conjunction with another mineral, galena, and this device was known as the cat's-whisker detector.

See also

• List of minerals
• Oleg Losev

References

External links

• Mineral galleries