Voltaite (original) (raw)
Formula:
K2Fe2+5Fe3+3Al(SO4)12 · 18H2O
Colour:
Green to greenish-black; oil-green to pale green in transmitted light.
Name:
Named after Count Alessandro Giuseppe Antonio Anastasio Volta (18 February 1745, Como, Italy - 5 March 1827, Como, Italy), physicist and pioneer in electricity who invented the electric battery.
Long-form identifier:
mindat:1:1:4203:7
ee97486d-7d83-4484-aff3-ccafdc50a243
Approved, 'Grandfathered' (first described prior to 1959)
7.CC.25
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
29.9.1.1
29 : HYDRATED ACID AND NORMAL SULFATES
9 : Miscellaneous
25.11.10
25 : Sulphates
11 : Sulphates of Fe and other metals
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference |
|---|---|---|
| Vlt | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Vlt | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Colour:
Green to greenish-black; oil-green to pale green in transmitted light.
Density:
2.645 g/cm3 (Measured) 2.663 g/cm3 (Calculated)
RI values:
n = 1.593 - 1.608
δ = 0.000
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Comments:
Anomalously biaxial sectors.
Mindat Formula:
K2Fe2+5Fe3+3Al(SO4)12 · 18H2O
Class (H-M):
m_3_m _(_4/_m_32/m ) - Hexoctahedral
Cell Parameters:
a = 27.254(8) Å
Unit Cell V:
20,243.74 ų (Calculated from Unit Cell)
Morphology:
Crystals (to 2 cm) are commonly octahedral and modified by the cube and dodecahedron. Other minor forms are rare. Granular, massive, and in efflorescences.(HoM)
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| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0015642 | Voltaite | Mereiter K (1972) Die kristallstruktur des voltaits, K2Fe2+5Fe3+3Al[SO4]12*18H2O Tschermaks Mineralogische und Petrographische Mitteilungen 18 185-202 | 1972 | 0 | 293 |
CIF Raw Data - click here to close
Geological Setting:
Fumaroles, solfataras, mud volcanoes and as an alteration product of pyrite-rich deposits in arid regions.
Geological Setting of Type Material:
Associated Minerals at Type Locality:
Other Members of this group:
Associated Minerals Based on Photo Data:
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Reference List:
Majzlan, Juraj, Schlicht, Hannes, Wierzbicka-Wieczorek, Maria, Giester, Gerald, Pöllmann, Herbert, Brömme, Beatrix, Doyle, Stephen, Buth, Gernot, Bender Koch, Christian (2013) A contribution to the crystal chemistry of the voltaite group: solid solutions, Mössbauer and infrared spectra, and anomalous anisotropy. Mineralogy and Petrology, 107 (2) 221-233 doi:10.1007/s00710-012-0254-2
Biagioni, Cristian, Mauro, Daniela, Pasero, Marco, Bonaccorsi, Elena, Lepore, Giovanni Orazio, Zaccarini, Federica, Skogby, Henrik (2020) Crystal-chemistry of sulfates from the Apuan Alps (Tuscany, Italy). VI. Tl-bearing alum-(K) and voltaite from the Fornovolasco mining complex. American Mineralogist, 105 (7). 1088-1098 doi:10.2138/am-2020-7320
Zhitova, Elena S., Sheveleva, Rezeda M., Kupchinenko, Anastasia N., Zolotarev, Andrey A., Pekov, Igor V., Nuzhdaev, Anton A., Davydova, Vesta O., Vlasenko, Natalia S., Plutakhina, Ekaterina Y., Yapaskurt, Vasiliy O., Schweigert, Peter E., Semenova, Tatiana F. (2023) The Crystal Chemistry of Voltaite-Group Minerals from Post-Volcanic and Anthropogenic Occurrences. Symmetry, 15 (12) 2126 doi:10.3390/sym15122126
This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the 
symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. 
- Good crystals or important locality for species. 
- World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.