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Rhomboclase

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Formula:
(H
 
5
O
 
2
)Fe
3+
 
(SO
 
4
)
 
2
· 2H
 
2
O
System:OrthorhombicColour:Blue, colourless, white, ...
Hardness:2
Name:From the Latin, rhombus, rhomb, plus Greek klasis, to break, in allusion to the basal cleavage and crystal form.


A common acidic alteration product of iron sulphides (pyrite, marcasite, pyrrhotite), frequently found as crusts and powders associated with other iron sulphates such as römerite, halotrichite etc.

Classification of Rhomboclase

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:6/C.08-10
Nickel-Strunz 10th (pending) edition ID:7.CB.55

7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
B : With only medium-sized cations
Dana 8th edition ID:29.1.1.1

29 : HYDRATED ACID AND NORMAL SULFATES
1 : Hydrated Acid Sulfates
Hey's CIM Ref.:25.10.6

25 : Sulphates
10 : Sulphates of Fe alone
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Type Occurrence of Rhomboclase

Type Locality:Smolník (Schmöllnitz; Szomolnok), Gelnica Co., Košice Region, Slovakia
Year of Discovery:1888
Geological Setting of type material:Pyritic ore body
Associated Minerals at type locality:
SzomolnokiteCopiapite

Occurrences of Rhomboclase

Geological Setting:Weathering of pyrite rich orebodies, especially in arid climates.

Physical Properties of Rhomboclase

Lustre:Sub-Vitreous, Pearly
Diaphaneity (Transparency):Transparent
Colour:Blue, colourless, white, yellow, light green, grey; colourless in transmitted light
Streak:White
Hardness (Mohs):2
Tenacity:Elastic
Cleavage:Perfect
On {001} perfect; on {110} good.
Fracture:Conchoidal, Fibrous
Density (measured):2.23 g/cm3
Density (calculated):2.21 g/cm3

Crystallography of Rhomboclase

Crystal System:Orthorhombic
Class (H-M):mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:Pnma {P21/n 21/m 21/a}
Cell Parameters:a = 9.72Å, b = 18.33Å, c = 5.42Å
Ratio:a:b:c = 0.53 : 1 : 0.296
Unit Cell Volume:V 965.67 ų (Calculated from Unit Cell)
Morphology:Crystals thin tabular {001}, with rhombic outline. Also forms stalactites with a radiating bladed structure.

Optical Data of Rhomboclase

Type:Biaxial (+)
RI values: nα = 1.534 nβ = 1.553 nγ = 1.638
2V:Measured: 27° , Calculated: 54°
Maximum Birefringence:δ = 0.104

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Low
Dispersion:r > v weak

Chemical Properties of Rhomboclase

Formula:
(H
 
5
O
 
2
)Fe
3+
 
(SO
 
4
)
 
2
· 2H
 
2
O
Simplified for copy/paste:(H5O2)Fe3+(SO4)2·2H2O
Essential elements:Fe, H, O, S
All elements listed in formula:Fe, H, O, S
Analytical Data:Slowly soluble in water.
Empirical Formula:
HFe
3+
 
(SO
 
4
)
 
2
· 4H
 
2
O

Relationship of Rhomboclase to other Species

Common Associates:
VoltaiteRömeriteHalotrichite
Related Minerals - Nickel-Strunz Grouping):

- +
7.CB.05Dwornikite
(Ni,Fe)SO
 
4
· H
 
2
O
7.CB.05Gunningite
ZnSO
 
4
· H
 
2
O
7.CB.05Kieserite
MgSO
 
4
· H
 
2
O
7.CB.05Poitevinite
(Cu,Fe,Zn)SO
 
4
· H
 
2
O
7.CB.05Szmikite
MnSO
 
4
· H
 
2
O
7.CB.05Szomolnokite
FeSO
 
4
· H
 
2
O
7.CB.05Cobaltkieserite
CoSO
 
4
· H
 
2
O
7.CB.07Sanderite
MgSO
 
4
· 2H
 
2
O
7.CB.10Bonattite
CuSO
 
4
· 3H
 
2
O
7.CB.15Aplowite
(Co,Mn,Ni)SO
 
4
· 4H
 
2
O
7.CB.15Boyleite
(Zn,Mg)SO
 
4
· 4H
 
2
O
7.CB.15Ilesite
(Mn,Zn,Fe)SO
 
4
· 4H
 
2
O
7.CB.15Rozenite
FeSO
 
4
· 4H
 
2
O
7.CB.15Starkeyite
MgSO
 
4
· 4H
 
2
O
7.CB.15Drobecite
CdSO
 
4
· 4H
 
2
O
7.CB.15Cranswickite
MgSO
 
4
· 4H
 
2
O
7.CB.20Chalcanthite
CuSO
 
4
· 5H
 
2
O
7.CB.20Jôkokuite
MnSO
 
4
· 5H
 
2
O
7.CB.20Pentahydrite
MgSO
 
4
· 5H
 
2
O
7.CB.20Siderotil
FeSO
 
4
· 5H
 
2
O
7.CB.25Bianchite
(Zn,Fe)SO
 
4
· 6H
 
2
O
7.CB.25Chvaleticeite
(Mn,Mg)SO
 
4
· 6H
 
2
O
7.CB.25Ferrohexahydrite
FeSO
 
4
· 6H
 
2
O
7.CB.25Hexahydrite
MgSO
 
4
· 6H
 
2
O
7.CB.25Moorhouseite
(Co,Ni,Mn)SO
 
4
· 6H
 
2
O
7.CB.25Nickelhexahydrite
(Ni,Mg,Fe)SO
 
4
· 6H
 
2
O
7.CB.30Retgersite
NiSO
 
4
· 6H
 
2
O
7.CB.35Bieberite
CoSO
 
4
· 7H
 
2
O
7.CB.35Boothite
CuSO
 
4
· 7H
 
2
O
7.CB.35Mallardite
MnSO
 
4
· 7H
 
2
O
7.CB.35Melanterite
FeSO
 
4
· 7H
 
2
O
7.CB.35Zincmelanterite
(Zn,Cu,Fe)SO
 
4
· 7H
 
2
O
7.CB.35Alpersite
(Mg,Cu)[SO
 
4
] · 7H
 
2
O
7.CB.40Epsomite
MgSO
 
4
· 7H
 
2
O
7.CB.40Goslarite
ZnSO
 
4
· 7H
 
2
O
7.CB.40Morenosite
NiSO
 
4
· 7H
 
2
O
7.CB.45Alunogen
Al
 
2
(SO
 
4
)
 
3
· 17H
 
2
O
7.CB.45Meta-alunogen
Al
 
2
(SO
 
4
)
 
3
· 12H
 
2
O
7.CB.50Aluminocoquimbite
FeAl(SO
 
4
)
 
3
· 9H
 
2
O
7.CB.55Coquimbite
Fe
 
2-x
Al
 
x
(SO
 
4
)
 
3
· 9H
 
2
O, x ~0.5
7.CB.55Paracoquimbite
Fe
 
2
(SO
 
4
)
 
3
· 9H
 
2
O
7.CB.60Kornelite
Fe
 
2
(SO
 
4
)
 
3
· 7H
 
2
O
7.CB.65Quenstedtite
Fe
 
2
(SO
 
4
)
 
3
· 10H
 
2
O
7.CB.70Lausenite
Fe
 
2
(SO
 
4
)
 
3
·6H
 
2
O
7.CB.75Lishizhenite
ZnFe
 
2
(SO
 
4
)
 
4
· 14H
 
2
O
7.CB.75Römerite
Fe
2+
 
Fe
3+
2
(SO
 
4
)
 
4
· 14H
 
2
O
7.CB.80Ransomite
CuFe
 
2
(SO
 
4
)
 
4
· 6H
 
2
O
7.CB.85Apjohnite
Mn
2+
 
Al
 
2
(SO
 
4
)
 
4
· 22H
 
2
O
7.CB.85Bílinite
Fe
2+
 
Fe
3+
2
(SO
 
4
)
 
4
· 22H
 
2
O
7.CB.85Dietrichite
(Zn,Fe
2+
 
,Mn
2+
 
)Al
 
2
(SO
 
4
)
 
4
· 22H
 
2
O
7.CB.85Halotrichite
FeAl
 
2
(SO
 
4
)
 
4
· 22H
 
2
O
7.CB.85Pickeringite
MgAl
 
2
(SO
 
4
)
 
4
· 22H
 
2
O
7.CB.85Redingtonite
(Fe
2+
 
,Mg,Ni)(Cr,Al)
 
2
(SO
 
4
)
 
4
·22H
 
2
O
7.CB.85Wupatkiite
(Co,Mg,Ni)Al
 
2
(SO
 
4
)
 
4
·22H
 
2
O
7.CB.90Meridianiite
MgSO
 
4
· 11H
 
2
O
Related Minerals - Hey's Index Grouping:

- +
25.10.1Szomolnokite
FeSO
 
4
· H
 
2
O
25.10.2Rozenite
FeSO
 
4
· 4H
 
2
O
25.10.3Siderotil
FeSO
 
4
· 5H
 
2
O
25.10.4Ferrohexahydrite
FeSO
 
4
· 6H
 
2
O
25.10.5Melanterite
FeSO
 
4
· 7H
 
2
O
25.10.7Lausenite
Fe
 
2
(SO
 
4
)
 
3
·6H
 
2
O
25.10.8Kornelite
Fe
 
2
(SO
 
4
)
 
3
· 7H
 
2
O
25.10.9Coquimbite
Fe
 
2-x
Al
 
x
(SO
 
4
)
 
3
· 9H
 
2
O, x ~0.5
25.10.10Paracoquimbite
Fe
 
2
(SO
 
4
)
 
3
· 9H
 
2
O
25.10.11Quenstedtite
Fe
 
2
(SO
 
4
)
 
3
· 10H
 
2
O
25.10.12Ferricopiapite
Fe
 
5
(SO
 
4
)
 
6
O(OH) · 20H
 
2
O
25.10.13Metahohmannite
Fe
3+
2
(SO
 
4
)
 
2
O · 4H
 
2
O
25.10.14Hohmannite
Fe
3+
2
(SO
 
4
)
 
2
O · 8H
 
2
O
25.10.15Butlerite
Fe
3+
 
(SO
 
4
)(OH) · 2H
 
2
O
25.10.16Parabutlerite
Fe
3+
 
(SO
 
4
)(OH) · 2H
 
2
O
25.10.17Amarantite
Fe
3+
2
(SO
 
4
)
 
2
O · 7H
 
2
O
25.10.18Fibroferrite
Fe
3+
 
(SO
 
4
)(OH) · 5H
 
2
O
25.10.19Hydroniumjarosite
(H
 
3
O)Fe
3+
3
(SO
 
4
)
 
2
(OH)
 
6
25.10.20Römerite
Fe
2+
 
Fe
3+
2
(SO
 
4
)
 
4
· 14H
 
2
O
25.10.21Bílinite
Fe
2+
 
Fe
3+
2
(SO
 
4
)
 
4
· 22H
 
2
O
25.10.22Copiapite
Fe
2+
 
Fe
3+
4
(SO
 
4
)
 
6
(OH)
 
2
· 20H
 
2
O

Other Names for Rhomboclase

Other Languages:
German:Rhomboklas
Russian:Ромбоклаз
Simplified Chinese:板铁矾

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Rhomboclase

Reference List:

- +
Krenner (1891) Ak. Értes., Budapest: 2: 96 (as Rhomboklas).

Scharizer (1901) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 35: 345 (as Saures Ferrisulfate).

Krenner (1907) Földtani Közlöny, Budapest (Magyarhone Földtani Torsulat): 37: 204.

Scharizer (1907) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 43: 113.

Scharizer (1921) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 56: 353.

Posnjak and Merwin (1922) Journal of the American Chemical Society: 44: 1983.

Scharizer (1927) Zeitschrift für Kristallographie, Mineralogie und Petrographie, Leipzig: 65: 335.

Krenner (1928) Centralblatt für Mineralogie, Geologie und Paleontologie, Stuttgart: 265.

Bandy (1938) American Mineralogist: 23: 740.

Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged: 436-437.

Tschermaks Mineralogische und Petrographische Mitteilungen: 21: 216-232.

Mineralogical Magazine (1974): 39: 611.

American Mineralogist (1995): 80: 408.

Peterson, R. C., Valyashko, E. and Wang, R. (2009): The atomic structure of (H3O)Fe3+(SO4)2 and rhomboclase, (H5O2)Fe3+(SO4)2•2H2O. Can. Mineral. 47, 625-634.

Internet Links for Rhomboclase

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  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Rhomboclase details from Handbook of Mineralogy (PDF)
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  • Localities for Rhomboclase

    The 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.
    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Australia
     
    • Queensland
    No reference listed
        • Mount Isa district
    Sielecki, R. (1988) The Mount Isa-Cloncurry mineral field. Mineralogical Record, Vol. 19, pg. 469-490.
    Austria
     
    • Styria
      • Leutschach
    Taucher, J. (1997)
    Bolivia
     
    • Oruro Department
      • Cercado Province
    [MinRec 32:476]
    [MinRec 32:479]
    Chile
     
    • Antofagasta Region
      • El Loa Province
        • Calama
          • Cerritos Bayos
    Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 437, 480.; Kampf, A.R.; Mills, S.J.; Housley, R.M.; Williams, P.A.; Dini, M. (2012): Alcaparrosaite, K3Ti4+Fe3+(SO4)4O(H2O)2, a new hydrophobic Ti4+ sulfate from Alcaparrosa, Chile. Mineralogical Magazine 76, 851-861.
    China
     
    • Xinjiang Autonomous Region
      • Hami Prefecture (Kumul Prefecture; Qumul Prefecture)
        • Hami Co. (Kumul Co.; Qumul Co.)
    Xu Ying-xia, Ding Kui-shou, Qin Ke-zhang, Miao Yu, Fang Tong-hui, Xu Xing-wang, and Sun He (2006): Geology in China 33(3), 605-616.
    Czech Republic
     
    • Bohemia (Böhmen; Boehmen)
      • Karlovy Vary Region
        • Krušné Hory Mts (Erzgebirge)
          • Jáchymov District (St Joachimsthal)
    Lapis 2002(7/8), 63-65
    Germany
     
    • Baden-Württemberg
      • Black Forest
        • Münstertal
          • St Trudpert
    Kleinander, R. (2009): Die antimonerzführenden Gänge im Münstergrund bei St. Trudpert. Mineralien-Welt 20 (5), 42-50.
        • Wolfach
          • Oberwolfach
            • Rankach valley
    Walenta, K. (1992): Die Mineralien des Schwarzwaldes. Chr. Weise Verlag, München, 336 pp. (in German)
    • Hesse
      • Richelsdorf District
        • Süss
          • Richelsdorf Smelter
    S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1992
    • Thuringia
      • Gera
        • Ronneburg U deposit
    T. Witzke & F. Rüger: Lapis 1998(7/8), 26-64
    T. Witzke & F. Rüger: Lapis 1998(7/8), 26-64
    Greece
     
    • Attikí Prefecture (Attica; Attika)
      • Lavrion District (Laurion; Laurium)
    Kolitsch, U., Rieck, B., Brandstätter, F., Schreiber, F., Fabritz, K. H., Blaß, G. & Gröbner, J. (2014): Neufunde aus dem altem Bergbau und den Schlacken von Lavrion (I). Mineralien-Welt 25 (1), 60-75 (in German). [identification announced; no description given yet]
    Hungary
     
    • Heves Co.
      • Mátra Mtns
        • Gyöngyösoroszi
    Farkas, I. M. & Weiszburg, T. G. (2009): Mitt. Österr. Mineral. Ges. 155, 57. (Abs.)
    • Veszprém Co.
      • Balaton Uplands
        • Tapolcai Basin
          • Lesenceistvánd
    Handbook of Mineralogy - Anthony, Bideaux, Bladh, Nichols
    Italy
     
    • Tuscany
      • Livorno Province
        • Elba Island
          • Capoliveri
    J. Göske, T. Witzke, H. Pöllmann, S. Stöber (1997) - Neufunde von Sekundarmineralen in der Lagerstatte Calamita/Insel Elba - Der Aufschluss, 48: 305-313.
    Peru
     
    • Pasco department
      • Pasco province
        • Cerro de Pasco
    Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 437, 515.
    Republic of Macedonia
     
    • Roszdan
    The Canadian Mineralogist Vol.32, pp. 649-665 (1994)
    Russia
     
    • Urals Region
      • Southern Urals
        • Chelyabinsk Oblast'
    Cesnokov, B., Kotrly, M. and Nisanbajev, T. (1998): Brennende Abraumhalden und Aufschlüsse im Tscheljabinsker Kohlenbecken - eine reiche Mineralienküche. Mineralien-Welt, 9 (3), 54-63 (in German).
    Slovakia
     
    • Košice Region
      • Gelnica Co.
    Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 437; Mineralogical Magazine (1974): 39: 610.
    Spain
     
    • Andalusia
      • Huelva
        • Minas de Riotinto
    MinMag 67(2):263-278
    A.M.I. Martins specimen
        • Nerva
    Romero, A., I. Gonzalez & E. Galan (2006): The role of efflorescent sulfates in the storage of trace elements in stream waters polluted by acid mine-drainage: the case of Pena del Hierro, southwestern Spain. Canadian Mineralogist 44, 1431-1446.
    Switzerland
     
    • Wallis (Valais)
      • Anniviers Valley
        • Saint-Luc
    Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): "Mineralienlexikon der Schweiz", Wepf (Basel), p. 349.
    Tajikistan
     
    • Viloyati Sogd (Viloyati Sughd; Viloyati Khodzhent; Viloyati Leninabad)
      • Zeravshan Range
        • Yagnob River
    PXRD (Lukasz Kruszewski)
    Ukraine
     
    • Donets'k Oblast' (Donetsk Oblast')
      • Gorlovka
        • Novyi Donbass
    Zanin, Y.N., Pisareva, G.M., Zamirailova, A.G., and Eder, V.G. (2009): Lithology and Mineral Resources 44(3), 267-269
    USA
     
    • Arizona
      • Cochise Co.
        • Mule Mts
          • Warren District
    No reference listed
              • Calumet and Arizona group of claims (Calumet and Arizona Mining Company group of claims)
    Grant, Raymond W., Richard A. Bideaux & Sidney A. Williams (2006), Minerals Added to the Arizona List 1995 to 2005: 3.
    Grant, Raymond W., Bideaux, R.A., and Williams, S.A. (2006) Minerals Added to the Arizona List 1995-2005: 7.
              • Queen Hill
    Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 531; Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 354, 415; Merwin, H.E. & E. Posnjak (1937), Sulphate encrustations in the Copper Queen mine, Bisbee, AZ, Am.Min.: 22: 567-571; Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 59.
    MinRec 12:311
      • Pinal Co.
        • Pinal Mts
          • Pioneer District
            • Superior
    Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 354, 388.
    • California
      • Inyo Co.
        • Coso Mts (Coso Range)
          • Coso District (New Coso District)
            • Coso Hot Springs
      • Shasta Co.
        • Klamath Mts
          • West Shasta Copper - Zinc District
            • Iron Mountain [town]
              • Iron Mountain
    MinRec 22:382; Mineralogical Record 22:381-382; Nordstrom, D. K. and Alpers, C. N. (1999): Negative pH, efflorescent mineralogy, and consequences for environmental restauration at the Iron Mountain Superfund site, California. Proc. Natl. Acad. Sci., USA 96, 3455-3462.
    • Georgia
      • Lincoln Co.
    Collected by Julian Gray 21 September 2010. Confirmed by XRD at the University of Georgia.
    • Nevada
      • Lander Co.
        • Lewis District
    NBMG Spec. Pub. 31 Minerals of Nevada
    • Utah
      • Utah Co.
        • East Tintic Mts
    UGMS Bull 117 Minerals and Mineral Localities of Utah
    • Virginia
      • Louisa Co.
    Minerals of Virginia 1990 by R. V. Dietrich
        • Lake Anna
    Minerals of Virginia 1990 by R. V. Dietrich
      • Rockbridge Co.
        • Lyndhurst-Vesuvius District
    Minerals of Virginia 1990 by R. V. Dietrich
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