Sepiolite
A valid IMA mineral species
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About Sepiolite
Formula:
Mg4(Si6O15)(OH)2 · 6H2O
Colour:
White, light gray or light yellow.
Lustre:
Sub-Vitreous, Silky, Dull, Earthy
Hardness:
2
Specific Gravity:
2.0 - 2.2
Crystal System:
Orthorhombic
Member of:
Name:
Named in 1847 by Ernst Friedrich Glocker from the Greek, "sepion," cuttle-fish bone, because of its low density and porous, bone like appearance. Originally named meerschaum by Abrahan Gottlieb Werner in 1788. Later translated as l'Ecume de mer. In 1794, the mineral was called keffekill by Richard Kirwan. Alexandre Brongniart called this mineral magnesite in 1807.
Type Locality:
Isostructural with:
Commonly found as compact masses of microscopic needles resulting in a low-density masses. May be an important constituent of "mountain leather". Free-standing acicular crystals not found in many localities.
May be confused with palygorskite. Results of García-Romero & Suárez (2010) indicate that no compositional gap exists between sepiolite and palygorskite.
May be confused with palygorskite. Results of García-Romero & Suárez (2010) indicate that no compositional gap exists between sepiolite and palygorskite.
Unique Identifiers
Mindat ID:
3621
Long-form identifier:
mindat:1:1:3621:0
Similar Names
| Sipylite | A synonym of Fergusonite | |
| Spilite | A rock classification type |
IMA Classification of Sepiolite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mg4Si6O15(OH)2 · 6H2O
Classification of Sepiolite
9.EE.25
9 : SILICATES (Germanates)
E : Phyllosilicates
E : Single tetrahedral nets of 6-membered rings connected by octahedral nets or octahedral bands
9 : SILICATES (Germanates)
E : Phyllosilicates
E : Single tetrahedral nets of 6-membered rings connected by octahedral nets or octahedral bands
74.3.1b.1
74 : PHYLLOSILICATES Modulated Layers
3 : Modulated Layers with joined strips
74 : PHYLLOSILICATES Modulated Layers
3 : Modulated Layers with joined strips
14.4.11
14 : Silicates not Containing Aluminum
4 : Silicates of Mg
14 : Silicates not Containing Aluminum
4 : Silicates of Mg
Mineral Symbols
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.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference |
|---|---|---|
| Sep | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Sep | Siivolam & Schmid (2007) | Siivolam, J. and Schmid, R. (2007) Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Web-version 01.02.07. IUGS Commission on the Systematics in Petrology. download |
| Sep | Whitney & Evans (2010) | Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187 doi:10.2138/am.2010.3371 |
| Sep | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
| Sep | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Sepiolite
Sub-Vitreous, Silky, Dull, Earthy
Transparency:
Translucent, Opaque
Colour:
White, light gray or light yellow.
Streak:
White
Hardness:
2 on Mohs scale
Tenacity:
Brittle
Parting:
Good, but grain sizes are generally small and no cleavage may be seen.
Fracture:
Fibrous
Comment:
May be in parallel fibrous aggregates
Density:
2.0 - 2.2 g/cm3 (Measured) 2.25 g/cm3 (Calculated)
Comment:
May be very light due to porous aggregates
Optical Data of Sepiolite
Type:
Biaxial (-)
RI values:
nα = 1.498 - 1.522 nβ = 1.507 - 1.553 nγ = 1.527 - 1.579
2V:
Measured: 20° to 70°, Calculated: 18°
Birefringence:
0.035
Max. Birefringence:
δ = 0.029 - 0.057
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.
Surface Relief:
Moderate
Dispersion:
none
Optical Extinction:
Z=c; parallel
Pleochroism:
Non-pleochroic
Comments:
May appear nearly isotropic. Meerschaum from Turkey reported at 1.517
Chemistry of Sepiolite
Mindat Formula:
Mg4(Si6O15)(OH)2 · 6H2O
Element Weights:
Elements listed:
Common Impurities:
Al,Ca,Fe,Ni
Crystallography of Sepiolite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pnna
Cell Parameters:
a = 5.21 Å, b = 26.73 Å, c = 13.5 Å
Ratio:
a:b:c = 0.195 : 1 : 0.505
Unit Cell V:
1,880.05 ų (Calculated from Unit Cell)
Morphology:
Needle-like fibers commonly in porous aggregates, also in fibrous sheets
Comment:
Pncn
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0004269 | Sepiolite | Post J E, Bish D L, Heaney P J (2007) Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of sepiolite American Mineralogist 92 91-97 |  | 2007 | Durango, Mexico | 0 | 293 |
| 0004270 | Sepiolite | Post J E, Bish D L, Heaney P J (2007) Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of sepiolite American Mineralogist 92 91-97 | | 2007 | Durango, Mexico | 0 | 293 |
| 0018529 | Sepiolite | Sanchez M, Garcia-Romero E, Suarez M, Silva I, Fuentes-Montero L, Martinez-Criado G (2011) Variability in sepiolite: Diffraction studies American Mineralogist 96 1443-1454 | 2011 | Batallones, Madrid, Spain | 0 | 498 | |
| 0018530 | Sepiolite | Sanchez M, Garcia-Romero E, Suarez M, Silva I, Fuentes-Montero L, Martinez-Criado G (2011) Variability in sepiolite: Diffraction studies American Mineralogist 96 1443-1454 | 2011 | Batallones, Madrid, Spain | 0 | 298 | |
| 0018531 | Sepiolite | Sanchez M, Garcia-Romero E, Suarez M, Silva I, Fuentes-Montero L, Martinez-Criado G (2011) Variability in sepiolite: Diffraction studies American Mineralogist 96 1443-1454 | 2011 | Grant County, New Mexico, USA | 0 | 498 | |
| 0018532 | Sepiolite | Sanchez M, Garcia-Romero E, Suarez M, Silva I, Fuentes-Montero L, Martinez-Criado G (2011) Variability in sepiolite: Diffraction studies American Mineralogist 96 1443-1454 | 2011 | Grant County, New Mexico, USA | 0 | 298 | |
| 0018533 | Sepiolite | Sanchez M, Garcia-Romero E, Suarez M, Silva I, Fuentes-Montero L, Martinez-Criado G (2011) Variability in sepiolite: Diffraction studies American Mineralogist 96 1443-1454 | 2011 | Fauske, Nordland, Norway | 0 | 498 | |
| 0018534 | Sepiolite | Sanchez M, Garcia-Romero E, Suarez M, Silva I, Fuentes-Montero L, Martinez-Criado G (2011) Variability in sepiolite: Diffraction studies American Mineralogist 96 1443-1454 | 2011 | Fauske, Nordland, Norway | 0 | 298 | |
| 0018363 | Sepiolite | Giustetto R, Levy D, Wahyudi O, Ricchiardi G, Vitillo J G (2011) Crystal structure refinement of a sepiolite/indigo Maya Blue pigment using molecular modelling and synchrotron diffraction European Journal of Mineralogy 23 449-466 | 2011 | Germany | 0 | 293 | |
| 0018364 | Sepiolite | Giustetto R, Levy D, Wahyudi O, Ricchiardi G, Vitillo J G (2011) Crystal structure refinement of a sepiolite/indigo Maya Blue pigment using molecular modelling and synchrotron diffraction European Journal of Mineralogy 23 449-466 | 2011 | synthetic | 0 | 293 | |
| 0015633 | Sepiolite | Brauner K, Preisinger A (1956) Struktur und entstehung des sepioliths Tschermaks Mineralogische und Petrographische Mitteilungen 6 120-140 | 1956 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.8 Å | (100) |
| 4.53 Å | (35) |
| 4.29 Å | (35) |
| 3.77 Å | (20) |
| 3.35 Å | (30vb) |
| 2.58 Å | (45) |
| 2.26 Å | (16b) |
Comments:
See also ICDD 13-595
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 16 : Low-? aqueous alteration of Hadean subaerial lithologies (see also #23) | |
| 17 : Marine authigenic Hadean minerals (see also #24) | |
| Near-surface Processes | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) | |
| 25 : Evaporites (prebiotic) | |
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 48 : Soil leaching zone minerals | <0.6 |
| 49 : Oxic cellular biomineralization (see also #44) | <0.54 |
Type Occurrence of Sepiolite
Synonyms of Sepiolite
Other Language Names for Sepiolite
Dutch:Sepioliet
French:Ecume de mer
L'écume de mer
L'écume de mer
German:Sepiolith
Meerschaum
Sepiolit
Meerschaum
Sepiolit
Russian:Сепиолит
Simplified Chinese:海泡石
Spanish:Sepiolita
Varieties of Sepiolite
| Aluminium-sepiolite | Al rich Sepiolite |
| Gunnbjarnite | A ferroan variety of Sepiolite. Originally reported from Greenland. |
Relationship of Sepiolite to other Species
Member of:
Other Members of Sepiolite Group:
| Falcondoite | (Ni,Mg)4Si6O15(OH)2 · 6H2O | Orth. |
| Ferrisepiolite | (Fe3+,Fe2+,Mg)4((Si,Fe3+)6O15)(O,OH)2 · 6H2O | Orth. mmm (2/m 2/m 2/m) |
| Loughlinite | Na2Mg3Si6O16 · 8H2O | Orth. mmm (2/m 2/m 2/m) |
Common Associates
Associated Minerals Based on Photo Data:
| 40 photos of Sepiolite associated with Hematite | Fe2O3 |
| 38 photos of Sepiolite associated with Sceptre Quartz | SiO2 |
| 38 photos of Sepiolite associated with Saponite | Ca0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O |
| 11 photos of Sepiolite associated with Dolomite | CaMg(CO3)2 |
| 9 photos of Sepiolite associated with Calcite | CaCO3 |
| 7 photos of Sepiolite associated with Quinzite Opal | SiO2 · nH2O |
| 6 photos of Sepiolite associated with Jasper | |
| 5 photos of Sepiolite associated with Quartz | SiO2 |
| 4 photos of Sepiolite associated with Amethyst | SiO2 |
| 3 photos of Sepiolite associated with Tsumebite | Pb2Cu(PO4)(SO4)(OH) |
Related Minerals - Strunz-mindat Grouping
| 9.EE. | Cairncrossite | Sr2Ca7-xNa2x(Si4O10)4(OH)2(H2O)15-x |
| 9.EE.05 | Bementite | Mn7Si6O15(OH)8 |
| 9.EE.07 | Innsbruckite | Mn33(Si2O5)14(OH)38 |
| 9.EE.10 | Brokenhillite | Mn8Si6O15(OH)10 |
| 9.EE.10 | Mcgillite | (Mn,Fe)8Si6O15(OH)8Cl2 |
| 9.EE.10 | Friedelite | Mn2+8Si6O15(OH,Cl)10 |
| 9.EE.10 | Pyrosmalite-(Mn) | Mn2+8Si6O15(OH,Cl)10 |
| 9.EE.10 | Pyrosmalite-(Fe) | Fe2+8Si6O15(OH,Cl)10 |
| 9.EE.15 | Nelenite | (Mn,Fe)16(Si12O30)(OH)14[As3+3O6(OH)3] |
| 9.EE.15 | Schallerite | Mn2+16As3Si12O36(OH)17 |
| 9.EE.20 | Palygorskite | ◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O |
| 9.EE.20 | Yofortierite | Mn2+Mn2+2Mn2+2◻2Si8O20(OH)2(H2O)4 · 4H2O |
| 9.EE.20 | Windhoekite | Fe3+(Fe3+1.67◻0.33)Ca2◻2Si8O20(OH)2(H2O)4(OH)2 · 6H2O |
| 9.EE.20 | Windmountainite | ◻Fe3+2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O |
| 9.EE.20 | Ikorskyite | KMn3+(Si4O10) · 3H2O |
| 9.EE.20 | Tuperssuatsiaite | Fe3+Fe3+2(Na◻)◻2Si8O20(OH)2(H2O)4 · 2H2O |
| 9.EE.20 | Unnamed (Na-Ca-Fe-Silicate-Hydrate) | NaCa(Fe2+,Al,Mn)5[Si8O19(OH)](OH)7 · 5H2O |
| 9.EE.25 | Loughlinite | Na2Mg3Si6O16 · 8H2O |
| 9.EE.25 | Falcondoite | (Ni,Mg)4Si6O15(OH)2 · 6H2O |
| 9.EE.25 | Kalifersite | (K,Na)5Fe3+7Si20O50(OH)6 · 12H2O |
| 9.EE.30 | Orlymanite | Ca4Mn3Si8O20(OH)6 · 2H2O |
| 9.EE.30 | Tungusite | Ca4Fe2Si6O15(OH)6 |
| 9.EE.30 | Gyrolite | NaCa16Si23AlO60(OH)8 · 14H2O |
| 9.EE.35 | Reyerite | (Na,K)2Ca14(Si,Al)24O58(OH)8 · 6H2O |
| 9.EE.35 | Kodamaite | Na3(Ca5Na)Si16O36(OH)4F2 · (14-x)H2O |
| 9.EE.35 | Truscottite | (Ca,Mn)14Si24O58(OH)8 · 2H2O |
| 9.EE.40 | Natrosilite | Na2Si2O5 |
| 9.EE.45 | Makatite | Na2Si4O8(OH)2 · 4H2O |
| 9.EE.50 | Varennesite | Na8Mn2Si10O25(OH,Cl)2 · 12H2O |
| 9.EE.55 | Raite | Mn2+Mn2+2Na2(◻1.75Ti0.25)Si8O20(OH)2(H2O)4 · Na(H2O)6 |
| 9.EE.60 | Intersilite | Na6Mn2+Ti[Si10O24(OH)](OH)3 · 4H2O |
| 9.EE.65 | Zakharovite | Na4Mn5Si10O24(OH)6 · 6H2O |
| 9.EE.65 | Shafranovskite | Na3K2(Mn,Fe,Na)4[Si9(O,OH)27](OH)2 · nH2O |
| 9.EE.70 | Zeophyllite | Ca13Si10O28(OH)2F8 · 6H2O |
| 9.EE.75 | Minehillite | (K,Na)2-3Ca28Zn4Al4Si40O112(OH)16 |
| 9.EE.80 | Fedorite | (Na,K)2-3(Ca4Na3)Si16O38(OH,F)2 · 3.5H2O |
| 9.EE.80 | Martinite | (Na,◻,Ca)12Ca4(Si,S,B)14B2O38(OH,Cl)2F2 · 4H2O |
| 9.EE.80 | Ellingsenite | Na5Ca6Si18O38(OH)13 · 6H2O |
| 9.EE.85 | Lalondeite | (Na,Ca)6(Ca,Na)3Si16O38(F,OH)2 · 3H2O |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Sepiolite
mindat.org URL:
https://www.mindat.org/min-3621.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
References for Sepiolite
Reference List:
Glocker, Ernst Friedrich (1847) Generum et specierum mineralium, secundum ordines naturales digestorum synopsis, omnium, quotquot adhuc reperta sunt, mineralium nomina complectens [A synopsis of the genera and species of minerals, according to their natural orders, including the names of all the minerals that have yet been discovered.]. Eduardus Anton. 348 pp. pp.185-195
Brindley, G. W. (1959) X-ray and electron diffraction data for sepiolite. American Mineralogist, 44 (5-6) 495-500
Van Olphen, H. (1966) Maya Blue: A Clay-Organic Pigment? Science, 154 (3749). 645-646 doi:10.1126/science.154.3749.645
Nagata, Hiroshi; Shimoda, Susumu; Sudo, Toshio (1974) On Dehydration of Bound Water of Sepiolite. Clays and Clay Minerals, 22 (3). 285-291 doi:10.1346/ccmn.1974.0220310
Rautureau, M.; Tchoubar, C. (1976) Structural Analysis of Sepiolite by Selected Area Electron Diffraction—Relations with Physico-Chemical Properties. Clays and Clay Minerals, 24 (1). 43-49 doi:10.1346/ccmn.1976.0240105
Güven, Necip; Carney, Leroy L. (1979) The Hydrothermal Transformation of Sepiolite to Stevensite and the Effect of Added Chlorides and Hydroxides. Clays and Clay Minerals, 27 (4). 253-260 doi:10.1346/ccmn.1979.0270403
D'Espinose de la Caillerie, J.-B., Fripiat, J. J. (1994) A reassessment of the 29Si MAS-NMR spectra of sepiolite and aluminated sepiolite. Clay Minerals, 29 (3) 313-318 doi:10.1180/claymin.1994.029.3.02
Post, J. E., Bish, D. L., Heaney, P. J. (2007) Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of sepiolite. American Mineralogist, 92 (1) 91-97 doi:10.2138/am.2007.2134
García-Romero, E., Suárez, M. (2010) On the Chemical Composition of Sepiolite and Palygorskite. Clays and Clay Minerals, 58 (1) 1-20 doi:10.1346/ccmn.2010.0580101
Giustetto, Roberto, Levy, Davide, Wahyudi, Olivia, Ricchiardi, Gabriele, Vitillo, Jenny G. (2011) Crystal structure refinement of a sepiolite/indigo Maya Blue pigment using molecular modelling and synchrotron diffraction. European Journal of Mineralogy, 23 (3) 449-466 doi:10.1127/0935-1221/2011/0023-2105
del Rio, M. S., Garcia-Romero, E., Suarez, M., da Silva, I., Fuentes-Montero, L., Martinez-Criado, G. (2011) Variability in sepiolite: Diffraction studies. American Mineralogist, 96 (10) 1443-1454 doi:10.2138/am.2011.3761
Stathopoulou, Elizabeth T., Suárez, Mercedes, García-Romero, Emilia, Río, Manuel Sánchez Del, Kacandes, George H., Gionis, Vassilis, Chryssikos, Georgios D. (2011) Trioctahedral entities in palygorskite: Near-infrared evidence for sepiolite-palygorskite polysomatism. European Journal of Mineralogy, 23 (4) 567-576 doi:10.1127/0935-1221/2011/0023-2112
Localities for Sepiolite
symbol to view information about a locality.
The Locality List
- 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).
All localities listed without proper references should be considered as questionable.
Argentina | |
| Hayase et al. (1970) |
Atlantic Ocean | |
| Ayupova et al. (2018) |
| Milinovic +6 other references | |
Australia | |
| Segnit (1973) |
| Sorrell (n.d.) |
| Sielecki (1988) |
| Updated list originally distributed by ... | |
| part of list University of Queensland |
| Sorrell (n.d.) |
| |
| Graham (2003) |
| Grguric (2003) |
Austria | |
| Niedermayr et al. (1995) |
| Pichler (2009) |
| Helmut Pristacz PXRD analysis 8/09 +1 other reference |
| Pristacz et al. (2009) |
| SIGMUND (1937a) |
| Exel (1993) |
| Huber et al. (1977) |
| Exel (1993) |
| Steinwender et al. (2012) |
| Strasser (1989) |
| Exel (1993) |
| Hackenberg (2003) |
| Exel (1993) |
| Neschen (n.d.) |
| Hollerer (1999) |
| Aufschluss 1972 (SB) +1 other reference |
| Exel (1993) |
| Exel (1993) |
| Neschen (n.d.) |
Belgium | |
| Hugget et al. (1996) +2 other references |
Brazil | |
| Bastos Neto et al. (2009) |
| Ratié et al. (2015) |
Canada | |
| Peatfield (n.d.) |
| C. J. A. Coats and R. Buchan (1979) |
| Confirmed from historically collected ... | |
| 162-165. +1 other reference |
| Springer (1989) |
| Sabina (1982) |
| geological survey of canada economic ... +1 other reference |
| Montgomery (n.d.) |
| Grice (1989) +1 other reference |
| Shang (2000) |
Chile | |
| XRD by Joachim Lorenz |
China | |
| Wenguang Li (1997) +1 other reference |
| Many of these pieces are referred to as ... | |
| Ruishi Yang and Wenguang Li (2001) |
| Ruishi Yang and Wenguang Li (2001) | |
| Ruishi Yang and Wenguang Li (2001) |
| Yongzhang Zhou et al. (1993) |
| Wenguang Li (1997) +1 other reference |
| Wenguang Li (1997) +1 other reference |
| Sakamoto et al. (1988) +1 other reference |
| Li et al. (2026) |
| Chang Xu (1985) |
| Ruishi Yang and Wenguang Li (2001) |
| Liu et al. (2015) |
| Industrial Minerals and Processing 33 (12) |
| Chang Xu (1985) |
| Ruishi Yang and Wenguang Li (2001) |
| Kaiji Yu (1981) |
| Ruishi Yang and Wenguang Li (2001) |
Colombia | |
| Econ Geol (2004) +2 other references |
| Castellanos-Alarcón et al. (2016) |
Czech Republic | |
| Pauliš P. Mineralogické lokality ... |
| Pauliš +4 other references | |
| Zikeš et al. (2011) |
| Ulrych |
| Houzar |
| Koníčková Š. et al. (2016) |
| Helmut Pristacz jr. PXRD analysis 8/09 (specimen in doubles collection in NHM Vienna) |
| Pelíšek | |
Dominican Republic | |
| Villanova-de-Benavent et al. (2014) |
| Domènech et al. (2022) | |
| Proenza et al. (2007) | |
France | |
| |
| G. Demarcq |
| The Quincyte pigments: fossil quinones ... |
| Bariand et al. (n.d.) |
| Manceau et al. (1985) |
| Guy Bernadi collection & Georges ... |
| "Les minéralisations associées au volcanisme andésitique de Biot-Villeneuve Loubet (Alpes Maritimes) |
Germany | |
| Weisenberger et al. (2014) +1 other reference |
| Weisenberger et al. (2014) | |
| Vielreicher R. M. (1991) |
| F. Müller: "Bayerns steinreiche Ecke" et al. (Hof) +1 other reference |
| F. Müller: "Bayerns steinreiche Ecke" et al. (Hof) |
| F. Müller: "Bayerns steinreiche Ecke" et al. (Hof) |
| Blaß et al. (2012) |
| Blaß et al. (2015) |
| Lapis 30 (7/8) |
Greece | |
| Färber (n.d.) |
| Sideridis et al. (2022) |
| Sideridis et al. (2022) | |
| Gauthier et al. (1991) |
Greenland | |
| Binzer et al. (1974) |
| Semenov (2001) +1 other reference |
| [var: Gunnbjarnite] American Mineralogist 37:1070-1071 |
Hungary | |
| Szakáll et al. (1996) |
| Szakáll & Jánosi (1996) |
India | |
| Mohapatra et al. (2003) |
Indonesia | |
| Sufriadin et al. (2012) |
Iran | |
Italy | |
| Bedognè et al. (1993) |
| Bedognè et al. (2006) |
| Vola (2020) |
| Glocker (1847) |
| www.webmineralshop.com (2001) |
| Ciriotti et al. (2011) |
| Piccoli et al. (2007) | |
| Piccoli et al. (2007) | |
| Exel (1987) |
| Garofalo et al. (2023) |
| Orlandi (2005) |
| Boscardin et al. (2011) |
| Zordan A. et al. (Vicenza) |
| Boscardin et al. (2011) +1 other reference |
Japan | |
| Masutomi Museum specimen (Kyoto) +1 other reference |
| - (n.d.) |
| Yongzhang Zhou et al. (1993) | |
| - (n.d.) |
| - (n.d.) |
| - (n.d.) |
| IMAI et al. (2000) |
| Imai (1978) |
| Ishibashi (1974) |
| Kato (2010) |
Kenya | |
| Stoessell et al. (1978) +1 other reference |
Kosovo | |
| Ilich et al. (2002) +1 other reference |
Madagascar | |
| Collection de Minéralogie (LMV) |
| Lautel (1953) |
| Lacroix (1941) |
| Behier (1963) | |
Malaysia | |
| Syed Hasan et al. (2018) |
| |
Mexico | |
| Forti (2006) |
| Jurgeit (2001) |
| Panczner (1987) |
Middle East | |
| Gross (1977) | |
Morocco | |
| Weiß (2006) |
Namibia | |
| Wilde (2023) |
| Buch et al. (1996) |
New Zealand | |
| Cox (1882) |
North Macedonia | |
| Todor Serafimovski et al. (2012) |
Norway | |
| Garmo (2003) |
| Berg et al. (2003) |
| Wel (1972) +1 other reference |
| Jahren et al. (1998) |
| Sigurd Stordal collection +1 other reference |
| Nordrum (2010) |
Poland | |
| Eligiusz Szełęg private collection |
| Lewandowska A. (OH) |
| Gaweł A. et al. (2008) | |
| Eligiusz Szełęg collection | |
| Lis et al. (1986) |
| Domań +2 other references |
| Harańczyk C. (1974) |
| JANECZEK J. | |
| Lis et al. (1986) |
Romania | |
| www.minerals-of-the-carpathians +1 other reference |
| Gheorghiţescu et al. (1972) | |
| Szakáll (2002) |
Russia | |
| Talovina et al. (2008) |
| Talovina et al. (2008) |
| Talovina et al. (2008) +2 other references |
| Talovina et al. (2008) | |
| Mazurov et al. (2007) |
| Левочская et al. (2021) |
| Pekin et al. (2010) +1 other reference | |
| ... |
| Talovina et al. (2003) |
| Grant et al. (2001) |
| [World of Stones 12:49] | |
Saudi Arabia | |
| Abuamarah et al. (2023) |
Slovakia | |
| Koděra (1986) |
| Koděra (1986) | |
| Koděra (1986) | |
| Ďuďa |
Slovenia | |
| Postl et al. (2015) |
Somalia | |
| - (2005) |
South America Plate | |
| Silva et al. (2025) |
| Schrank et al. (2024) | |
South Korea | |
| old "Chuseihokudo" specimen on sale at ... | |
Spain | |
| Calvo Rebollar (2016) |
| Calvo (2016) |
| Alejandro Sánchez Jiménez |
| Calvo (2008) |
| Calvo (2008) |
| Calvo (2008) |
| Calvo et al. (2014) |
| Yongzhang Zhou et al. (1993) |
| Pozo et al. (1993) | |
| Stvdia Geologica Salmanticensia |
| Fernández Macarro et al. (1988) |
| Fernández Macarro et al. (1988) | |
| Buey et al. (2025) | |
| Buey et al. (2025) | |
| Buey et al. (2025) | |
| Buey et al. (2025) | |
| Petrov (n.d.) |
| Petrov (n.d.) |
| Calvo (2018) |
| Ruishi Yang and Wenguang Li (2001) |
| Rodríguez et al. (1994) | |
| www.foro-minerales.com (n.d.) | |
| Alonso-Zarza et al. (2011) |
Sweden | |
| Gatedal (n.d.) +1 other reference |
| |
Switzerland | |
| Kipfer et al. (1979) +1 other reference |
Tajikistan | |
| Badalov et al. (1977) |
Tanzania | |
| Sampson (1966) |
Turkey | |
| Echle (1967) |
| Güngör Yeşilova et al. (2023) |
| |
| Karakaya et al. (2004) |
| Altay et al. (2010) |
UK | |
| Golley et al. (1995) |
| Power et al. (1997) |
| Power et al. (1997) | |
| Turner et al. (2010) |
| Day (1999) |
| Livingstone (2002) |
USA | |
| U. S. Geological Survey Open-File ... |
| Graeme (1981) |
| Anthony et al. (1995) |
| Anthony et al. (1995) |
| Anne Seminaris specimen +1 other reference |
| Anthony et al. (1995) |
| AmMin 27:512 | |
| Kauffman et al. (1943) +2 other references | |
| Anthony et al. (1995) | |
| Färber (n.d.) |
| a spectroscopic exploration. Economic ... +1 other reference |
| Hanks (1884) +1 other reference | |
| Post (1984) |
| Hardie (1968) +2 other references | |
| Fleischer (1972) +2 other references |
| Woodford et al. (1941) +3 other references |
| Dunning et al. (2005) |
| Otton +2 other references |
| - (2005) |
| Hewett (1956) +2 other references |
| XRD confirmed by Tony Kampf. +1 other reference |
| Collected by and in the collection of ... | |
| Collected by and in the collection of ... | |
| Leo (1967) +2 other references |
| Cooper et al. (1986) |
| Palache et al. (1944) |
| Similar samples from identical geology ... |
| Januzzi et al. (1976) +1 other reference |
| USGS Circular 1059 pp129-137 |
| Smith et al. (1986) | |
| Marc V. Hurst (2012) |
| Smith et al. (1986) |
| Cook (1978) |
| Cook (1978) | |
| Cook (1978) | |
| Ballard (1948) |
| Tank (1972) +2 other references | |
| Ream (2004) |
| Identified and verified by SEM/EDS and ... |
| Ross (2007) |
| Sherwood et al. (1998) |
| Gnanou (2018) |
| Gnanou (2018) |
| Guilbert and Zeihen 1964 +1 other reference |
| Buck et al. (2006) |
| Castor et al. (2004) |
| Castor et al. (2004) |
| Castor et al. (2004) |
| www.globalgeo.com.au (2018) |
| Castor et al. (2004) |
| Rocks & Minerals. Nov. 1999. |
| Güven et al. (1979) | |
| Castor et al. (2004) | |
| Maertens (2007) |
| Germine (1987) +1 other reference |
| McLemore et al. (1996) |
| Northrop et al. (1996) | |
| - (2005) | |
| Northrop et al. (1996) | |
| USGS Bull 1451 |
| USGS Bull 1451 | |
| USGS Bull 1451 | |
| Northrop et al. (1996) |
| Tankersley et al. (2016) |
| John H. Betts (2009) |
| New York State Museum collection |
| Rocks & Min. V.71 +1 other reference |
| NY State Museum spec. no. 13870 |
| Chamberlain et al. (2023) | |
| Brindley (1959) | |
| Hadley et al. (1945) |
| Dana et al. (1892) |
| - (2005) |
| Bargar et al. (1997) |
| Samuel S. Gordon +1 other reference |
| ... | |
| Lapham et al. (1976) |
| Miller |
| Bullock (1981) |
| Bullock (1981) +1 other reference |
| Bullock (1981) | |
| USGS TEI #514 +1 other reference |
| Bullock (1981) |
| Bullock (1981) |
| Rocks & Min. Vol. 71 (1996) |
| Robin D. Tibbit (deceased) |
| Rocks & Min.: 14:112-113. |
| - (2005) |
| Werner et al. (2006) | |
| Cannon (1975) |
Venezuela | |
| Urbani (1996) |
| Franco Urbani (2009) |
Valley, Stevens County, Washington, USA