Epidote (original) (raw)
A valid IMA mineral species - grandfathered
About EpidoteHide
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Formula:
(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Colour:
Yellowish-green, green, brownish-green, black
Specific Gravity:
3.38 - 3.49
Crystal System:
Monoclinic
Name:
Named in 1801 by Rene Just Haüy from the Greek επιδοσιζ ("epidosis"), meaning "increase", in allusion to the crystal characteristic of one longer side at the base of the prism.
Unique IdentifiersHide
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Long-form identifier:
mindat:1:1:1389:1
ad7fdfab-07df-483c-a51d-c515b0234bcd
IMA Classification of EpidoteHide
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Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca2(Al2Fe3+)[Si2O7][SiO4]O(OH)
Classification of EpidoteHide
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9.BG.05a
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
58.2.1a.7
58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
16.21.2
16 : Silicates Containing Aluminum and other Metals
21 : Aluminosilicates of Fe and Ca
Mineral SymbolsHide
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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 |
|---|---|---|
| Ep | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Ep | Kretz (1983) | Kretz, R. (1983) Symbols of rock-forming minerals. American Mineralogist, 68, 277–279. |
| Ep | 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 |
| Ep | 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 |
| Ep | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
| Ep | 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 |
Pronunciation of EpidoteHide
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Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Sorry, your browser doesn't support HTML5 audio. | Jolyon Ralph | United Kingdom |
Physical Properties of EpidoteHide
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Transparency:
Transparent, Translucent, Opaque
Colour:
Yellowish-green, green, brownish-green, black
Cleavage:
Perfect
Perfect on {001}, imperfect on {100}
Fracture:
Irregular/Uneven
Density:
3.38 - 3.49 g/cm3 (Measured) 3.43(3) g/cm3 (Calculated)
Optical Data of EpidoteHide
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RI values:
_n_α = 1.715 - 1.751 _n_β = 1.725 - 1.784 _n_γ = 1.734 - 1.797
2V:
Measured: 90° to 116°, Calculated: 62° to 84°
δ = 0.019 - 0.046
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Comments:
X= colourless, pale yellow, pale green
Y= greenish yellow
Z= yellowish green
Chemistry of EpidoteHide
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Mindat Formula:
(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Common Impurities:
Al,Mg,Mn
Crystallography of EpidoteHide
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Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 8.8877(14) Å, b = 5.6275(8) Å, c = 10.1517(12) Å
β = 115.383(14)°
Ratio:
a:b:c = 1.579 : 1 : 1.804
Unit Cell V:
458.73 ų (Calculated from Unit Cell)
Morphology:
Crystals prismatic to 35 cm, also stubby, rarely tabular or pseudo-octahedral. Fibrous, coarse to finely granular, massive. Prismatic crystals may show a pseudo-hexagonal cross-section.
Twinning:
On {100}, contact, lamellar, common.
Crystallographic forms of EpidoteHide
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Crystal Atlas:
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Crystal StructureHide
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| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0000041 | Epidote | Ito T (1947) The structure of epidote (HCa2(Al,Fe)Al2Si3O13) American Mineralogist 32 309-321 |  |
1947 | 0 | 293 | |
| 0000226 | Epidote | Dollase W A (1971) Refinement of the crystal structures of epidote, allanite and hancockite American Mineralogist 56 447-464 | |
1971 | 0 | 293 | |
| 0000229 | Epidote | Dollase W A (1971) Refinement of the crystal structures of epidote, allanite and hancockite American Mineralogist 56 447-464 | |
1971 | 0 | 293 | |
| 0000308 | Epidote | Gabe E J, Portheine J C, Whitlow S H (1973) A reinvestigation of the epidote structure: Confirmation of the iron location sample HEP American Mineralogist 58 218-223 | |
1973 | 0 | 293 | |
| 0000309 | Epidote | Gabe E J, Portheine J C, Whitlow S H (1973) A reinvestigation of the epidote structure: Confirmation of the iron location sample LEP American Mineralogist 58 218-223 | |
1973 | 0 | 293 | |
| 0002248 | Epidote | Giuli G, Bonazzi P, Menchetti S (1999) Al-Fe disorder in synthetic epidotes: A single-crystal X-ray diffraction study American Mineralogist 84 933-936 | |
1999 | 0 | 293 | |
| 0016949 | Epidote | Nagashima M, Akasada M (2010) X-ray Rietveld and 57Fe Mossbauer studies of epidote and piemontite on the join Ca2Al2FeSi3O12(OH) - Ca2Al2MnSi3O12(OH) formed by hydrothermal synthesis American Mineralogist 95 1237-1246 | 2010 | synthetic | 0 | 293 | |
| 0016950 | Epidote | Nagashima M, Akasada M (2010) X-ray Rietveld and 57Fe Mossbauer studies of epidote and piemontite on the join Ca2Al2FeSi3O12(OH) - Ca2Al2MnSi3O12(OH) formed by hydrothermal synthesis American Mineralogist 95 1237-1246 | 2010 | synthetic | 0 | 293 | |
| 0016951 | Epidote | Nagashima M, Akasada M (2010) X-ray Rietveld and 57Fe Mossbauer studies of epidote and piemontite on the join Ca2Al2FeSi3O12(OH) - Ca2Al2MnSi3O12(OH) formed by hydrothermal synthesis American Mineralogist 95 1237-1246 | 2010 | synthetic | 0 | 293 | |
| 0016952 | Epidote | Nagashima M, Akasada M (2010) X-ray Rietveld and 57Fe Mossbauer studies of epidote and piemontite on the join Ca2Al2FeSi3O12(OH) - Ca2Al2MnSi3O12(OH) formed by hydrothermal synthesis American Mineralogist 95 1237-1246 | 2010 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder DiffractionHide
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Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.900 Å | (100) |
| 2.679 Å | (100) |
| 2.688 Å | (70) |
| 4.02 Å | (50) |
| 2.599 Å | (50) |
| 2.460 Å | (50) |
| 3.40 Å | (40) |
Comments:
Bourg d'Oisans, France.
Geological EnvironmentHide
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Geological Setting:
Regional and contact metamorphic rocks. Saussuritisation (alteration of plagioclase).
Type Occurrence of EpidoteHide
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Place of Conservation of Type Material:
Muséum Nationale d’Histoire Naturelle, Paris, France, numbers H3408 and H3445 (cotype).
Synonyms of EpidoteHide
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Other Language Names for EpidoteHide
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Simplified Chinese:绿帘石
Traditional Chinese:綠簾石
Varieties of EpidoteHide
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| Allanite-Epidote | Epidote enriched with REE and Y transitive to allanite-(Ce) or -(Y). Its REE+Y content is below 0.5 apfu. Sometimes such epidotes are selectively enriched in Eu (as at the Tsakhirin Khuduk deposit in Mongolian Altai). |
|---|---|
| Beryllium-bearing Epidote | A beryllium-bearing variety of epidote. |
| Bucklandite (of Hermann) | Morphological variety of dipyramidal Epidote. It is usually dark-colored, REE-bearing, transitive to Allanite-(Ce). The first description of the variety was made by Hermann in 1833 from Akhmatovskaya Kop' (Southern Urals).See also Bucklandite (of Lévy)... |
| Rosstrevorite | A fibrous stellate variety of epidote, from Rosstrevor, Co. Down, Ireland (Greg and Lettsom, 1858). |
| Tawmawite | A Cr-bearing epidote.Originally reported from Tawmaw (Tawhmaw; Taw Maw), Myitkyina-Mogaung District, Kachin State, Myanmar (Burma). |
| Withamite | A Mn-rich variety of epidote.Originally reported from Glen Coe, Strathclyde (Argyllshire), Scotland, UK. May be confused with pinkish varieties of clinozoisite and zoisite ("thulite"). |
| Yttroepidote | Yttrium-bearing epidote with a Y+REE content below 0.5 apfu. Transitive to allanite-(Y).First described from Slyudorudnik, Southern Urals, in 1959. |
Relationship of Epidote to other SpeciesHide
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Other Members of this group:
Common AssociatesHide
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Associated Minerals Based on Photo Data:
Related Minerals - Strunz-mindat GroupingHide
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Other InformationHide
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Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Epidote in petrologyHide
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An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.
- Igneous rock
- Sedimentary rock and sediment
- Metamorphic rock
- Meta-igneous rock
* Metavolcanic rock
* Metabasalt
* Chlorite-actinolite metabasalt
* Glaucophane-lawsonite metabasalt - High-grade metamorphic rock
* Amphibolite
* Epidote amphibolite - Very low to low-grade metamorphic rock
* Spilite
* Greenschist
* Chlorogrisonite schist
* Cucalite
* Gadriolite
* Paradiorite
* Valrheinite
* Greenstone - Gneiss
* Granitic gneiss
* Protogine - Schist
* Amphibole schist
* Epidote-amphibole schist
* Glaucophane schist
* Epidote-glaucophane schist
* Mica schist
* Sericite schist
* Epidote-sericite schist - Contact metamorphic rock
* Granofels
* Hornfels
* Albite-epidote hornfels
* Crossite-pumpellyite granofels
* Chlorite-epidote granofels - Metasomatic-rock
* Adinole
* Contact adinole
* Tuffaceous adinole
* Skarn
* Calc-skarn
* Rodingite
* Unakite
* Propylite
* Fault-related alkaline metasomatite
* Albitized granite
* Albitized gneiss - Epidosite
- Meta-igneous rock
Internet Links for EpidoteHide
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References for EpidoteHide
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Reference List:
Armbruster, Thomas, Bonazzi, Paola, Akasaka, Masahide, Bermanec, Vladimir, Chopin, Christian, Gieré, Reto, Heuss-Assbichler, Soraya, Liebscher, Axel, Menchetti, Silvio, Pan, Yuanming, Pasero, Marco (2006) Recommended nomenclature of epidote-group minerals. European Journal of Mineralogy, 18 (5) 551-567 doi:10.1127/0935-1221/2006/0018-0551
Significant localities for EpidoteHide
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Showing 23 significant localities out of 10,491 recorded on mindat.org.
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.
Locality ListHide
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- 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.
| Austria | |
|---|---|
| Carinthia Wolfsberg District Wolfsberg ⓘ Gertrusk |
Niedermayr et al. (1995) |
| Salzburg Zell am See District Neukirchen am Großvenediger Knappenwand area ⓘ Knappenwand |
Mason (1976) +1 other reference |
| Belgium | |
| Wallonia Walloon Brabant Rebecq Quenast ⓘ Porphyry quarries |
Stöber (1895) +2 other references |
| Ecuador | |
| Guayas Province Guayaquil Canton Guayaquil Pascuales La Germania ⓘ C.V. Hormigones |
Alejandro Felix Gutierrez |
| France (TL) | |
| Auvergne-Rhône-Alpes Isère Grenoble ⓘ Le Bourg-d'Oisans (TL) | Haüy (1801a) +1 other reference |
| Provence-Alpes-Côte d'Azur Alpes-de-Haute-Provence Barcelonnette Saint-Paul-sur-Ubaye ⓘ Tête de Toillies south-west slope (Col Blanchâtre; Roc della Niera south-west slope) |
Piccoli (2002) +1 other reference |
| Réunion Cilaos ⓘ Cascade Bras Rouge |
Serge Lavarde Collection |
| ⓘ La Chapelle |
Serge Lavarde Collection |
| Guatemala | |
| Quiché Department Joyabaj Palibatz ⓘ Palibatz No. 2 Mine |
USGS Bulletin 1034 |
| Italy | |
| Piedmont Metropolitan City of Turin Balme ⓘ Colle del Paschiet (Colle Paschietto) |
Borson (1811) +15 other references |
| Usseglio ⓘ Falin Lake |
Alpinisti M. (1981) +1 other reference |
| Mexico | |
| Baja California San Quintín Municipality San Fernando ⓘ Sauzalito |
Peninsular Range Collection - Curtis ... |
| North Macedonia | |
| Prilep Municipality Čanište ⓘ Unnamed pegmatite (Dimov Dol) |
Bermanec et al. (2001) +1 other reference |
| Pakistan | |
| Gilgit-Baltistan Roundu District Haramosh Mts. ⓘ Tormiq Valley |
Weerth (1991) |
| Portugal | |
| Leiria Óbidos Santa Maria e São Pedro e Sobral da Lagoa ⓘ Avarela quarry (Casal da Avarela) |
|
| South Africa | |
| Mpumalanga Ehlanzeni District Municipality Kruger National Park ⓘ Tshokwane | PMPB Meulenbeld collection Photo ID: ... |
| UK | |
| Scotland Highland Fort William and Ardnamurchan ⓘ Glen Coe |
[var: Withamite] C. Hintze: "Handbuch der Mineralogie" (1897) +2 other references |
| USA | |
| Alaska Prince of Wales-Hyder Census Area Ketchikan Mining District Prince of Wales Island ⓘ Green Monster Mountain |
Mason (1976) +1 other reference |
| California Calaveras County Valley Springs area ⓘ Calaveras River Canyon |
Jake Harper: Field work |
| Connecticut Hartford County Glastonbury South Glastonbury ⓘ Gas pipeline excavation |
Betts (1999) |
| Middlesex County Haddam ⓘ Hazen quarry (Epidote locality) |
Davis (1901) +2 other references |
| Tolland County Coventry ⓘ US Route 6 Willimantic Bypass expressway road cuts |
Harvard Mineralogical Museum No. 119199 +1 other reference |
| Nevada Mineral County Hawthorne Mining District (Pamlico Mining District) ⓘ Julie Claim |
Benham et al. (1985) |