Mineralogy Database

Voltaite Mineral Data

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General Voltaite Information

Help on Chemical  Formula: Chemical Formula: K2Fe++5Fe+++3Al(SO4)12•18(H2O)
Help on Composition: Composition: Molecular Weight = 2,028.99 gm
   Potassium   3.85 %  K     4.64 % K2O
   Aluminum    1.33 %  Al    2.51 % Al2O3
   Iron       22.02 %  Fe   17.70 % FeO / 11.81 % Fe2O3
   Hydrogen    1.79 %  H    15.98 % H2O
   Sulfur     18.96 %  S    47.35 % SO3
   Oxygen     52.04 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K2Fe2+5Fe3+3Al(SO4)12•18(H2O)
Help on Environment: Environment: Solfatara and fumaroles associated with volcanic activity and continental evaporite deposits.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1841
Help on Locality: Locality: Pozzuoli near Naples, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the Italian physicist, Alessandro G. A. A. Volta (1745-1841).
Help on Name Pronunciation: Name Pronunciation: Voltaite Say VOLTAITE
Help on Synonym: Synonym: ICSD 9254
  PDF 20-1388

Voltaite Image

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  Voltaite   Alunogen

Comments: Dark greenish-black crystals of voltaite on white alunogen.
Location: Carola Mine, Freital, Dresden, Saxony, Germany. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

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  Szomolnokite   Voltaite

Comments: Whitish crystalline crust of voltaite on crystals of brown szomolnokite.
Location: Alcaparrosa Mine, Cerritos Bayos, Chile. Scale: Picture size 1 cm.
© John Veevaert

Voltaite Crystallography

Help on Cell Dimensions: Cell Dimensions: a = 27.178, Z = 16; V = 20,074.86 Den(Calc)= 2.69
Help on Crystal System: Crystal System: Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: F d3c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.54(1), 3.41(0.9), 5.57(0.7),

Physical Properties of Voltaite

Help on Cleavage: Cleavage: None
Help on Color: Color: Greenish black, Dark green, Olive green, Black.
Help on Density: Density: 2.6 - 2.8, Average = 2.7
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Crystalline - Fine - Occurs as well-formed fine sized crystals.
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Hardness: Hardness: 3-3.5 - Calcite-Copper Penny
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Silky
Help on Streak: Streak: grayish green

Optical Properties of Voltaite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.002 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.001 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2232,KPDmeas= 0.2224,KC= 0.2229
Ncalc = 1.58 - 1.62
Help on Optical Data: Optical Data: Isotropic, n=1.593-1.608.

Calculated Properties of Voltaite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.69 gm/cc
note: Specific Gravity of Voltaite =2.69 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.006347623
Boson Index = 0.993652377
Help on Photoelectric: Photoelectric: PEVoltaite = 8.02 barns/electron
U=PEVoltaite x relectron= 21.59 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 55.65 (Gamma Ray American Petroleum Institute Units)
Concentration of Voltaite per GRapi unit = 1.80 (%)

Estimated Radioactivity from Voltaite - barely detectable


Voltaite Classification

Help on  Dana Class: Dana Class: (29)Hydrated Acid and Sulfates
  (29.09)with miscellaneous formulae
  (29.09.01)Voltaite Group Voltaite K2Fe5Fe3Al(SO4)12•18(H2O) F d3c 4/m 3 2/m Zincovoltaite K2Zn5Fe3Al(SO4)12•18(H2O) F d3c 4/m 3 2/m Pertlikite! K2(Fe,Mg)2(Mg,Fe)4Fe2Al(SO4)12•18H2O I 41/acd 4/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 07.CC.25 07 - SULFATES (SELENATES, TELLURATES)
  07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O
  07.CC -With medium-sized and large cations
07.CC.25 Monsmedite? H8K2Tl2(SO4)8•11(H2O) F d3c 4/m 3 2/m
07.CC.25 Voltaite K2Fe5Fe3Al(SO4)12•18(H2O) F d3c 4/m 3 2/m
07.CC.25 Zincovoltaite K2Zn5Fe3Al(SO4)12•18(H2O) F d3c 4/m 3 2/m
07.CC.25 Pertlikite! K2(Fe,Mg)2(Mg,Fe)4Fe2Al(SO4)12•18H2O I 41/acd 4/m 2/m 2/m

Other Voltaite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Voltaite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Dana No: Strunz No: 07.CC.25





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