Hydrozincite

Summary

Hydrozincite, also known as zinc bloom or marionite, is a white carbonate mineral consisting of Zn5(CO3)2(OH)6. It is usually found in massive rather than crystalline form.

Hydrozincite
General
CategoryCarbonate mineral
Formula
(repeating unit)
Zn5(CO3)2(OH)6
IMA symbolHznc[1]
Strunz classification5.BA.15
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupC2/m
Unit cella = 13.58 Å, b = 6.28 Å,
c = 5.41 Å; β = 95.51°, Z = 2
Identification
ColorWhite to grey, stained pale pink, or pale yellow or brown; colourless in transmitted light.
Crystal habitLathlike or bladed crystals uncommon, in fibrous, stalactitic, reniform, pisolitic aggregates; also earthy, chalky, massive
TwinningContact twinning on {100}
CleavagePerfect on {100}
FractureIrregular/uneven
TenacityVery brittle
Mohs scale hardness2–2+12
LusterSilky, pearly, dull, earthy
StreakWhite
DiaphaneityTransparent, translucent
Specific gravity3.5–4
Optical propertiesBiaxial (−)
Refractive indexnα = 1.630 nβ = 1.642 nγ = 1.750
Birefringenceδ = 0.120
2V angleMeasured: 40°, calculated: 40°
Dispersionrelatively strong
Ultraviolet fluorescenceFluoresces pale blue to lilac under UV
SolubilityReadily soluble in acids.
References[2][3][4]

It occurs as an oxidation product of zinc ores and as post mine incrustations. It occurs associated with smithsonite, hemimorphite, willemite, cerussite, aurichalcite, calcite and limonite.[2]

It was first described in 1853 for an occurrence in Bad Bleiberg, Carinthia, Austria and named for its chemical content.[3]

References edit

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Handbook of Mineralogy
  3. ^ a b Mindat
  4. ^ Webmineral data
  • Mineral galleries data

External links edit

  •   Media related to Hydrozincite at Wikimedia Commons