Epidote
A valid IMA mineral species - grandfathered
This page kindly sponsored in memory of Laszlo Z. Valachi
About Epidote
Formula:
(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Colour:
Yellowish-green, green, brownish-green, black
Lustre:
Vitreous
Hardness:
6
Specific Gravity:
3.38 - 3.49
Crystal System:
Monoclinic
Member of:
Name:
Named in 1801 by René Just Haüy from the Greek ἐπίδοσις (epidosis), referring to the crystal’s characteristic in which one side of its base is more extended than the other.
A common Ca-Fe-silicate that occurs in a large variety of rocks.
There is an asymmetric miscibility gap in the monoclinic Al-Fe(III)-epidote solid solution series (Strens, 1964, 1965; Raith, 1976).
Visit gemdat.org for gemological information about Epidote.
There is an asymmetric miscibility gap in the monoclinic Al-Fe(III)-epidote solid solution series (Strens, 1964, 1965; Raith, 1976).
Visit gemdat.org for gemological information about Epidote.Unique Identifiers
Mindat ID:
1389
Long-form identifier:
mindat:1:1:1389:1
Similar Names
| Epidote-(Ga) | A synonym of 'Unnamed (Ga-analogue of Epidote)' | |
| Epidote-(Pb) | A synonym of Hancockite | |
| Epidote-(Sr) | A valid IMA mineral species | (CaSr)(AlAlFe3+)O[Si2O7][SiO4](OH) |
IMA Classification of Epidote
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca2Fe3+Al2(Si2O7)(SiO4)O(OH)
Classification of Epidote
9.BG.05a
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
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)
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
16 : Silicates Containing Aluminum and other Metals
21 : Aluminosilicates of Fe and Ca
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 for Standard |
|---|---|---|
| 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 Epidote
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Epidote
Vitreous
Transparency:
Transparent, Translucent, Opaque
Colour:
Yellowish-green, green, brownish-green, black
Streak:
Colourless
Hardness:
6 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
Perfect on {001}, imperfect on {100}
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 Epidote
Type:
Biaxial (-)
RI values:
nα = 1.715 - 1.751 nβ = 1.725 - 1.784 nγ = 1.734 - 1.797
2V:
Measured: 90° to 116°, Calculated: 62° to 84°
Max. Birefringence:
δ = 0.019 - 0.046
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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
strong r > v
Pleochroism:
Strong
Comments:
X= colourless, pale yellow, pale green
Y= greenish yellow
Z= yellowish green
Y= greenish yellow
Z= yellowish green
Chemistry of Epidote
Mindat Formula:
(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Element Weights:
Common Impurities:
Al,Mg,Mn
Chemical Analysis
Oxide wt%:
| 1 | 2 | |
|---|---|---|
| SiO2 | 37.43 % | 38.2 % |
| TiO2 | 0.08 % | |
| Al2O3 | 23.37 % | 24.9 % |
| Cr2O3 | 0.06 % | |
| Fe2O3 | 12.71 % | 10.1 % |
| MnO | 0.19 % | 0.1 % |
| MgO | 0.05 % | 0.3 % |
| CaO | 22.43 % | 23.2 % |
| K2O | 0.01 % | |
| FeO | 1.5 % | |
| SnO2 | 0.8 % | |
| H2O | 1.9 % | |
| Total: | 96.33 % | 101 % |
Empirical formulas:
| Sample ID | Empirical Formula |
|---|---|
| 2 | Ca2(Al2.30Fe3+0.60Fe2+0.05Sn0.05)O(Si2O7)(SiO4)(OH) |
Sample references:
| ID | Locality | Reference | Notes |
|---|---|---|---|
| 1 | Weiß‑Spitze eclogites, Virgen valley, Lienz District, Tyrol, Austria | Sample ES‑11 represents a fine‑grained, strongly banded eclogite forming the host rock at the locality. EMPA analysis. | |
| 2 | Tin bearing skarns, Cassiar, Liard Mining Division, British Columbia, Canada | Wet chemical and Optical emission spectrography analysis of a Sn-rich epidote from hand-picked crystal fragments from pyroxene-skarn |
Crystallography of Epidote
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Cell Parameters:
a = 8.8877(14) Å, b = 5.6275(8) Å, c = 10.1517(12) Å
β = 115.383(14)°
β = 115.383(14)°
Ratio:
a:b:c = 1.579 : 1 : 1.804
Unit Cell V:
458.73 ų (Calculated from Unit Cell)
Z:
2
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 Epidote
Crystal Atlas:
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Epidote no.9 - Goldschmidt (1913-1926)
Epidote no.94 - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by
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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) |
|---|---|---|---|---|---|---|---|
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 0000229 | Epidote | Dollase W A (1971) Refinement of the crystal structures of epidote, allanite and hancockite American Mineralogist 56 447-464 | | 1971 | 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 | |
| 0000041 | Epidote | Ito T (1947) The structure of epidote (HCa2(Al,Fe)Al2Si3O13) American Mineralogist 32 309-321 | | 1947 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Loading XRD data...
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 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) | |
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 39 : High-? metamorphism (blueschist, eclogite, ultrahigh ? facies) | |
| 40 : Regional metamorphism (greenschist, amphibolite, granulite facies) | |
| 43 : Shear-induced minerals (including mylonite/slickensides) |
Geological Setting:
Regional and contact metamorphic rocks. Saussuritisation (alteration of plagioclase).
Type Occurrence of Epidote
Place of Conservation of Type Material:
Muséum Nationale d’Histoire Naturelle, Paris, France, numbers H3408 and H3445 (cotype).
Synonyms of Epidote
Other Language Names for Epidote
Croatian:Epidot
Dutch:Epidoot
Finnish:Epidootti
French:Épidote
Pistachite
Pistachite
German:Epidot
Acanthikon
Acanticonit
Acantikonit
Achmatit
Aescherit
Allochit
Arendalit
Arendit
Eisenepidot
Epidotit
Escherit
Pistacit
Pistazit
Posstrevorit
Puschkinit
Pushkinit
Selphinit
Thallit
Acanthikon
Acanticonit
Acantikonit
Achmatit
Aescherit
Allochit
Arendalit
Arendit
Eisenepidot
Epidotit
Escherit
Pistacit
Pistazit
Posstrevorit
Puschkinit
Pushkinit
Selphinit
Thallit
Hebrew:אפידוט
Hungarian:Epidot
Italian:Epidoto
Japanese:緑簾石
Lithuanian:Epidotas
Polish:Epidot
Portuguese:Epídoto
Romanian:Epidot
Russian:Эпидот
Simplified Chinese:绿帘石
Slovak:Epidot
Spanish:Epidota
Acanticonita
Achmatita
Aescherita
Allochita
Arendalita
Arendita
Epidotita
Escherita
Pistacita
Posstrevorita
Puschkinita
Pushkinita
Selphinita
Thallita
Acanticonita
Achmatita
Aescherita
Allochita
Arendalita
Arendita
Epidotita
Escherita
Pistacita
Posstrevorita
Puschkinita
Pushkinita
Selphinita
Thallita
Swedish:Epidot
Traditional Chinese:綠簾石
Ukrainian:Епідот
Varieties of Epidote
| Allanite-Epidote | Epidote enriched with REE and Y transitive to allanite-(Ce) or allanite-(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 Species
Member of:
Other Members of Epidote Group:
| Clinozoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Epidote-(Sr) | (CaSr)(AlAlFe3+)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Hancockite | (CaPb)(AlAlFe3+)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Heflikite | (CaCa)(AlAlSc)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Mukhinite | (CaCa)(AlAlV3+)O[Si2O7][SiO4](OH) | Mon. |
| Niigataite | (CaSr)(AlAlAl)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Piemontite | (CaCa)(AlAlMn3+)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Piemontite-(Pb) | (CaPb)(AlAlMn3+)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Piemontite-(Sr) | (CaSr)(AlAlMn3+)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| Tweddillite | (CaSr)(Mn3+AlMn3+)O[Si2O7][SiO4](OH) | Mon. 2/m : P21/m |
| 'Unnamed (Fe3+ analogue of Piemontite-(Pb))' | (CaPb)(Fe3+AlMn3+)O[Si2O7][SiO4](OH) | |
| 'Unnamed (Fe3+-analogue of Piemontite)' | (CaCa)(Fe3+AlMn3+)O[Si2O7][SiO4](OH) | |
| 'Unnamed (Fe3+-analogue of Piemontite-(Sr))' | (CaSr)(Fe3+AlMn3+)O[Si2O7][SiO4](OH) | |
| 'Unnamed (Ga-analogue of Epidote)' | (CaCa)(AlAlGa3+)O[Si2O7][SiO4](OH) |
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 2,520 photos of Epidote associated with Quartz | SiO2 |
| 1,376 photos of Epidote associated with Prehnite | Ca2Al2Si3O10(OH)2 |
| 696 photos of Epidote associated with Calcite | CaCO3 |
| 519 photos of Epidote associated with Albite | Na(AlSi3O8) |
| 389 photos of Epidote associated with Andradite | Ca3Fe3+2(SiO4)3 |
| 355 photos of Epidote associated with 'Byssolite' | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| 305 photos of Epidote associated with Native Copper | Cu |
| 302 photos of Epidote associated with Magnetite | Fe2+Fe3+2O4 |
| 290 photos of Epidote associated with Diopside | CaMgSi2O6 |
| 264 photos of Epidote associated with Titanite | CaTiO(SiO4) |
Related Minerals - Strunz-mindat Grouping
| 9.BG. | Alumovesuvianite | Ca19AlAl4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
| 9.BG. | Alnaperbøeite-(Ce) | Ca(Ce2.5Na0.5)(AlAl2Al)[Si2O7][SiO4]3O(OH)2 |
| 9.BG. | Zilbermintsite-(La) | (CaLa5)(Fe3+Al3Fe2+)[Si2O7][SiO4]5O(OH)3 |
| 9.BG. | Heflikite | (CaCa)(AlAlSc)O[Si2O7][SiO4](OH) |
| 9.BG. | Magnesiovesuvianite | Ca19MgAl4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG. | Zoisite-(Pb) | (CaPb)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG. | Shuiskite-(Cr) | Ca2Cr3+Cr3+2[Si2O6OH][SiO4](OH)2O |
| 9.BG. | Radekškodaite Group | |
| 9.BG.05 | Dissakisite-(La) | (CaLa)(AlAlMg)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Manganiandrosite-(Ce) | (Mn2+Ce)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Dissakisite-(Ce) | (CaCe)(AlAlMg)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Sm) | (CaSm)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Hancockite | (CaPb)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Dollaseite-(Ce) | (CaCe)(MgAlMg)F[Si2O7][SiO4](OH) |
| 9.BG.05a v | 'Unnamed (Ga-analogue of Epidote)' | (CaCa)(AlAlGa3+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Clinozoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Epidote-(Sr) | (CaSr)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Vanadoandrosite-(Ce) | (Mn2+Ce)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Vanadoallanite-(La) | (CaLa)(V3+AlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | 'Unnamed (Mg-analogue of Ferriallanite-(Ce))' | (CaCe)(Fe3+AlMg)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriallanite-(La) | (CaLa)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Uedaite-(Ce) | (Mn2+Ce)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Tweddillite | (CaSr)(Mn3+AlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Åskagenite-(Nd) | (Mn2+Nd)(AlAlFe3+)O[Si2O7][SiO4]O |
| 9.BG.05 | Piemontite-(Pb) | (CaPb)(AlAlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Ce) | (CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(La) | (CaLa)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Y) | (CaY)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Piemontite | (CaCa)(AlAlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Akasakaite-(Ce) | (CaCe)(AlAlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Manganiandrosite-(La) | (Mn2+La)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Akasakaite-(La) | (CaLa)(AlAlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Vanadoakasakaite-(La) | (CaLa)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Khristovite-(Ce) | (CaCe)(MgAlMn2+)F[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriakasakaite-(La) | (CaLa)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Ferriandrosite-(La) | (Mn2+La)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | 'Androsite-(Ce)' | (Mn2+Ce)(AlAlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Vielleaureite-(Ce) | Mn2+Ce(MgAlMn2+)(Si2O7)(SiO4)F(OH) |
| 9.BG.05 | Ferriandrosite-(Ce) | (Mn2+Ce)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriallanite-(Ce) | (CaCe)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | 'Unnamed (Mn3+-analogue of Ferriakasakaite-(Ce))' | (CaCe)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Vanadoakasakaite-(Ce) | (CaCe)(V3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Piemontite-(Sr) | (CaSr)(AlAlMn3+)O[Si2O7][SiO4](OH) |
| 9.BG.05 | Niigataite | (CaSr)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Ferriakasakaite-(Ce) | (CaCe)(Fe3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Allanite-(Nd) | (CaNd)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | 'UM1989-32-SiO:AlCaFeHREE' | (Ca0.5◻0.5REE)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 9.BG.05a | Mukhinite | (CaCa)(AlAlV3+)O[Si2O7][SiO4](OH) |
| 9.BG.05b | Manganiakasakaite-(La) | (CaLa)(Mn3+AlMn2+)O[Si2O7][SiO4](OH) |
| 9.BG.10 | Zoisite | (CaCa)(AlAlAl)O[Si2O7][SiO4](OH) |
| 9.BG.15 | Macfallite | Ca2Mn3+3(SiO4)(Si2O7)(OH)3 |
| 9.BG.15 | Sursassite | Mn2+2Al3(SiO4)(Si2O7)(OH)3 |
| 9.BG.20 | Pumpellyite-(Al) | Ca2AlAl2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Shuiskite-(Mg) | Ca2MgCr3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Julgoldite-(Fe2+) | Ca2Fe2+Fe3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Okhotskite | Ca2Mn2+Mn3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Julgoldite-(Mg) | Ca2MgFe3+2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Poppiite | Ca2V3+V3+2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Julgoldite-(Fe3+) | Ca2Fe3+Fe3+2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Pumpellyite-(Fe2+) | Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Pumpellyite-(Fe3+) | Ca2Fe3+Al2[Si2O6OH][SiO4](OH)2O |
| 9.BG.20 | Pumpellyite-(Mg) | Ca2MgAl2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.20 | Pumpellyite-(Mn2+) | Ca2Mn2+Al2[Si2O6OH][SiO4](OH)2(OH) |
| 9.BG.25 | Ganomalite | Pb9Ca5Mn(Si2O7)4(SiO4)O |
| 9.BG.25 | Wayneburnhamite | Pb9Ca6(Si2O7)3(SiO4)3 |
| 9.BG.30 | Rustumite | Ca10(Si2O7)2(SiO4)(OH)2Cl2 |
| 9.BG.35 | Modraite | Ca19Fe2+Al4(Al6Fe2+2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG.35 | Fluorvesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(F,OH)9 |
| 9.BG.35 | Vesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
| 9.BG.35 | Milanriederite | (Ca18[REE])Fe3+Al4(Mg4Al4)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG.35 | Manaevite-(Ce) | (Ca13Ce4[H2O]2)Mg(Al3Mg)(Mg3Ti3Fe3+2)(◻4)◻[Si2O7]4[(SiO4)8(H4O4)2]O(OH)9 |
| 9.BG.35 | Hongheite | Ca19Fe2+Al4(Fe3+,Mg)8(◻4)B[Si2O7]4[(SiO4)10]O(OH,O)9 |
| 9.BG.35 | Wiluite | Ca19MgAl4(Al,Mg)8(B,◻)4◻[Si2O7]4[(SiO4)10]O(O,OH)9 |
| 9.BG.35 | Cyprine | Ca19Cu2+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10](OH)(OH)9 |
| 9.BG.35 | Manganvesuvianite | Ca19Mn3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
| 9.BG.40 | Vyuntspakhkite-(Y) | (Y,Yb)4Al2.5-1.5(Si,Al)1.5-2.5(SiO4)4O(OH)7 |
| 9.BG.45 | Dellaite | Ca6Si3O11(OH)2 |
| 9.BG.50 | Ferriperbøeite-(Ce) | CaCe3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Perbøeite-(La) | CaLa3(AlAl2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Perbøeite-(Ce) | CaCe3(AlAl2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Gatelite-(Ce) | CaCe3(AlAl2Mg)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.50 | Ferriperbøeite-(La) | CaLa3(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 |
| 9.BG.55 | Västmanlandite-(Ce) | CaCe3(MgAl2Mg)[Si2O7][SiO4]3F(OH)2 |
| 9.BG.60 | Radekškodaite-(La) | (CaLa5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 |
| 9.BG.60 | Radekškodaite-(Ce) | (CaCe5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 |
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.
Epidote in petrology
An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.
Internet Links for Epidote
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References for Epidote
Reference List:
Seki., Yôtarô (1959) Relation between chemical composition and lattice constants of epidote. American Mineralogist, 44 (7-8) 720-730
Chatterjee, Niranjan Deb (1962) Vesuvianite-epidote paragenesis as a product of greenschist facies of regional metamorphism in the Western Alps. Beiträge zur Mineralogie und Petrographie, 8 (6). 432-439 doi:10.1007/bf01082095
Strens, R. G. J. (1964) Epidotes of the Borrowdale Volcanic rocks of central Borrowdale. Mineralogical Magazine and Journal of the Mineralogical Society, 33 (265) 868-886 doi:10.1180/minmag.1964.033.265.04
Strens, R. G. J. (1965) Stability and relations of the Al-Fe epidotes. Mineralogical Magazine and Journal of the Mineralogical Society, 35 (271) 464-475 doi:10.1180/minmag.1965.035.271.02
Strens, R. G. J. (1966) Properties of the Al–Fe–Mn epidotes. Mineralogical Magazine and Journal of the Mineralogical Society, 35 (275) 928-944 doi:10.1180/minmag.1966.035.275.04
Keith, Terry E. C., Muffler, L. J. Patrick, Cremer, and Marcelyn (1968) Hydrothermal epidote formed in the Salton Sea geothermal system, California. American Mineralogist, 53 (9-10) 1635-1644
Dollase, W. A. (1971) Refinement of the crystal structures of epidote, allanite, and hancockite. American Mineralogist, 56 (3-4) 447-464
Gabe, Eric J., Portheine, Jan C., Whitlow, and Simon H. (1973) A reinvestigation of the epidote structure: Confirmation of the iron location. American Mineralogist, 58 (3-4) 218-223
Hörmann, Paul-Karl; Raith, Michael (1973) Erratum: Bildungsbedingungen von Al-Fe(III)-Epidoten. Contributions to Mineralogy and Petrology, 40 (1). p.86. doi:10.1007/bf00371769
Hörmann, Paul-Karl, Raith, Michael (1973) Bildungsbedingungen von Al-Fe (III)-Epidoten. Contributions to Mineralogy and Petrology, 38 (4) 307-320 doi:10.1007/bf00373596
Raith, Michael (1976) The Al-Fe(III)epidote miscibility gap in a metamorphic profile through the penninic series of the Tauern window, Austria. Contributions to Mineralogy and Petrology, 57 (1). p.99-117. doi:10.1007/bf00392855
Brown, E. H. (1977) Phase equilibria among pumpellyite, lawsonite, epidote and associated minerals in low grade metamorphic rocks. Contributions to Mineralogy and Petrology, 64 (2) 123-136 doi:10.1007/bf00371507
SMITH, R. E., PERDRIX, J. L., PARKS, T. C. (1982) Burial Metamorphism in the Hamersley Basin, Western Australia. Journal of Petrology, 23 (1) 75-102 doi:10.1093/petrology/23.1.75
Sakai, Chihiro, Higashino, Toshio, Enami, Masaki (1984) REE-bearing epidote from Sanbagawa pelitic schists, central Shikoku, Japan. GEOCHEMICAL JOURNAL, 18 (2) 45-53 doi:10.2343/geochemj.18.45
Kvick, Å., Pluth, J. J., Richardson, J. W., Smith, J. V. (1988) The ferric ion distribution and hydrogen bonding in epidote: a neutron diffraction study at 15 K. Acta Crystallographica Section B Structural Science, 44 (4) 351-355 doi:10.1107/s0108768188001491
Absar, Ahsan (1991) Hydrothermal Epidote - An Indicator of Temperature and Fluid Composition. Journal Geological Society of India, 38 (6). 625-628 doi:10.17491/jgsi/1991/380610
Janeczek, Janusz, Sachanbinski, Michael (1992) Babingtonite, Y-Al-rich titanite, and zoned epidote from the Strzegom pegmatites, Poland. European Journal of Mineralogy, 4 (2) 307-320 doi:10.1127/ejm/4/2/0307
Holland, T. J. B., Redfern, Simon A. T., Pawley, A. R. (1996) Volume behavior of hydrous minerals at high pressure and temperature: II. Compressibilities of lawsonite, zoisite, clinozoisite, and epidote. American Mineralogist, 81 (3). 341-348 doi:10.2138/am-1996-3-408
Giuli, Gabriele; Bonazzi, Paola; Menchetti, Silvio (1999) Al-Fe disorder in synthetic epidotes: A single-crystal X-ray diffraction study. American Mineralogist, 84 (5). p.933-936.
Gieré, R., Sorensen, S. S. (2004) Allanite and Other REE-Rich Epidote-Group Minerals. In Reviews in Mineralogy and Geochemistry Vol. 56. Mineralogical Society of America. p.431-493. doi:10.2138/gsrmg.56.1.431
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
NAGASHIMA, Mariko (2006) Hydrothermal syntheses of epidote and piemontites on the join Ca2Al2Fe3+Si3O12(OH)-Ca2Al2Mn3+Si3O12(OH) at relatively low pressures of 200-400 MPa. Journal of Mineralogical and Petrological Sciences, 101 (1) 1-9 doi:10.2465/jmps.101.1
White, Alistair J. R., Laukamp, Carsten, Stokes, Mark A., Legras, Monica, Pejcic, Bobby (2017) Vibrational spectroscopy of epidote, pumpellyite and prehnite applied to low-grade regional metabasites. Geochemistry: Exploration, Environment, Analysis, 17 (4) 315-333 doi:10.1144/geochem2016-007
Pan, TANG; Shun, GUO (2019) Epidote records subduction-zone metamorphic fluid actions. Acta Petrologica Sinica, 35 (7). p.2045-2060. doi:10.18654/1000-0569/2019.07.07
Nagashima, Mariko; Mihailova, Boriana (2023) Optimal Raman-scattering signal for estimating the Fe3+ content on the clinozoisite–epidote join. European Journal of Mineralogy, 35 (2). 267-283 doi:10.5194/ejm-35-267-2023
Significant localities for Epidote
Showing 23 significant localities out of 11,245 recorded on mindat.org.
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.
Austria | |
| Niedermayr et al. (1995) |
| Treimer (2001) +7 other references |
Belgium | |
| Stöber (1895) +2 other references |
Ecuador | |
| Alejandro Felix Gutierrez |
France (TL) | |
| Haüy (1801a) +1 other reference |
| Piccoli (2002) +1 other reference |
| Serge Lavarde Collection |
| Serge Lavarde Collection | |
Guatemala | |
| USGS Bulletin 1034 |
Italy | |
| Borson (1811) +15 other references |
| Alpinisti M. (1981) +1 other reference |
Mexico | |
| Peninsular Range Collection - Curtis ... |
North Macedonia | |
| Bermanec et al. (2001) +1 other reference |
Pakistan | |
| Weerth (1991) |
Portugal | |
| |
South Africa | |
| PMPB Meulenbeld collection Photo ID: ... |
UK | |
| [var: Withamite] C. Hintze: "Handbuch der Mineralogie" (1897) +2 other references |
USA | |
| Mason (1976) +1 other reference |
| Jake Harper: Field work |
| Betts (1999) |
| Davis (1901) +2 other references |
| Harvard Mineralogical Museum No. 119199 +1 other reference |
| Benham et al. (1985) |
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Alchuri alpine-type clefts, Alchuri, Shigar Valley, Shigar District, Gilgit-Baltistan, Pakistan