Named for the Dioskouri (Castor and Polydeuces), twin brothers of Greek mythology. The name relates to "the existence of two polytypes that are indistinguishable in appearance but different in symmetry, unit cell configuration and XRD pattern."

Type Locality:

ⓘ Arsenatnaya fumarole, Second scoria cone, Northern Breakthrough (North Breach), Great Fissure eruption (Main Fracture), Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia

Chemically related to centennialite; compare Unnamed (Ca-Cu Chloride).

Two polytypes, intergrown with each other, are known.

Unique IdentifiersHide

Mindat ID:

47598

Long-form identifier:

mindat:1:1:47598:1

IMA Classification of DioskouriiteHide

IMA status:

Approved

Approval year:

2016

First published:

2021

Type description reference:

Pekov, Igor V., Zubkova, Natalia V., Zolotarev, Andrey A., Yapaskurt, Vasiliy O., Krivovichev, Sergey V., Belakovskiy, Dmitry I., Lykova, Inna, Vigasina, Marina F., Kasatkin, Anatoly V., Sidorov, Evgeny G., Pushcharovsky, Dmitry Yu. (2021) Dioskouriite, CaCu₄Cl₆(OH)₄·4H₂O: A New Mineral Description, Crystal Chemistry and Polytypism. Minerals, 11 (1) 90 doi:10.3390/min11010090

Classification of DioskouriiteHide

Strunz-mindat (2026):

3.DA.70

3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
A : With Cu, etc., without Pb

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Symbol	Source	Reference for Standard
Dio	IMA–CNMNC	Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of DioskouriiteHide

Lustre:

Vitreous

Transparency:

Transparent

Colour:

Bright green, Grey

Tenacity:

Brittle

Cleavage:

Distinct/Good
One distinct (believed to be (100)) and one imperfect

Fracture:

Irregular/Uneven

Density:

2.75(1) g/cm³ (Measured) 2.765 g/cm³ (Calculated)

Comment:

Calculated value above is for dioskouriite-2O and 2.820 g cm−3 for dioskouriite-2M.

Optical Data of DioskouriiteHide

Type:

Biaxial (+)

RI values:

n_α = 1.695(4) n_β = 1.715(8) n_γ = 1.750(6)

2V:

Measured: 70° (10), Calculated: 75.5°

Max. Birefringence:

δ = 0.055
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.

Surface Relief:

Moderate

Dispersion:

very strong, r < v

Pleochroism:

Strong

Comments:

Z (grass green) > Y (yellowish-green) > X (pale yellowish-green)

Chemistry of DioskouriiteHide

Mindat Formula:

CaCu₄Cl₆(OH)₄ · 4H₂O

Element Weights:

Element	% weight
Cu	39.282 %
Cl	32.874 %
O	19.781 %
Ca	6.194 %
H	1.869 %

Calculated from ideal end-member formula.

Elements listed:

Ca, Cl, Cu, H, O - search for minerals with similar chemistry

Crystallography of DioskouriiteHide

Polytype:

Formula:

Crystal System:

Class (H-M)

Space Group:

Space Group Setting:

Cell Parameters:

Ratio:

Unit Cell Volume (calc):

Comment:

Dioskouriite-2M	Dioskouriite-2O
CaCu₄Cl₆(OH)₄ · 4H₂O	CaCu₄Cl₆(OH)₄ · 4H₂O
Monoclinic	Orthorhombic
2/m - Prismatic	222 - Disphenoidal
P2₁/b	P2₁2₁2₁
P2₁/c
a = 7.2792(8) Å, b = 10.3000(7) Å, c = 20.758(2) Å β = 100.24(1)°	a = 7.3193(7) Å, b = 10.371(1) Å, c = 20.560(3) Å
a:b:c = 0.707 : 1 : 2.015	a:b:c = 0.706 : 1 : 1.982
V 1,531.56 Å³ (Calculated from Unit Cell)	V 1,560.68 Å³ (Calculated from Unit Cell)

X-Ray Powder DiffractionHide

Powder Diffraction Data:

d-spacing	Intensity
10.29 Å	(100)
5.960 Å	(22)
5.754 Å	(7)
5.492 Å	(11)
5.170 Å	(16)
5.035 Å	(13)
2.737 Å	(28)
2.417 Å	(8)

Locality:

Arsenatnaya fumarole, Second scoria cone, Northern Breakthrough (North Breach), Great Fissure eruption (Main Fracture), Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia

Reference:

Comments:

Data for the 2M polytype

Geological EnvironmentHide

Paragenetic Mode(s):

Paragenetic Mode	Earliest Age (Ga)
Stage 7: Great Oxidation Event	<2.4
45b : [Other oxidized fumarolic minerals]

Type Occurrence of DioskouriiteHide

Type Locality:

ⓘ Arsenatnaya fumarole, Second scoria cone, Northern Breakthrough (North Breach), Great Fissure eruption (Main Fracture), Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia

General Appearance of Type Material:

Green sword-like crystals in groups or crusts up to 1 × 2 mm2

Place of Conservation of Type Material:

collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia (registration number 4803/1), catalog number 95282.

Geological Setting of Type Material:

Fumarolic. Possibly formed through interactions involving high-temperature sublimate minerals, fumarolic gas and atmospheric water vapor at temperatures not higher than 150 C.

Associated Minerals at Type Locality:

Anhydrite	Avdoninite	Baryte	Belloite	Carnallite
Chalcocyanite	Chlorothionite	Chrysothallite	Clinoenstatite	Diopside
Eriochalcite	Feodosiyite	Flinteite	Fluorophlogopite	Gypsum
Halite	Hematite	Kainite	Mellizinkalite	Mitscherlichite
Powellite	Pseudobrookite	Romanorlovite	Sanguite	Sanidine
Sellaite	Sylvite	Tenorite

Reference:

Synonyms of DioskouriiteHide

IMA2015-106

Other Language Names for DioskouriiteHide

Dutch:Dioskouriiet

German:Dioskouriit

Related Minerals - Strunz-mindat Grouping Hide

3.DA.	Parahibbingite	Fe₂(OH)₃Cl	Trig. 3m(32/m) : R3m
3.DA.	Centennialite	CaCu₃Cl₂(OH)₆ · nH₂O (n ~ 0.7)	Trig. 3m(32/m) : P3m1
3.DA.	Bounahasite	Cu⁺Cu²⁺₂(OH)₃Cl₂	Mon. 2/m
3.DA.	Muonionalustaite	Ni₃(OH)₄Cl₂ · 4H₂O	Mon. 2/m : B2/m
3.DA.05	Melanothallite	Cu₂Cl₂O	Orth. mmm(2/m2/m2/m) : Fddd
3.DA.10c	Haydeeite	Cu₃Mg(OH)₆Cl₂	Trig. 3m(32/m) : P3m1
3.DA.10b	Clinoatacamite	Cu₂(OH)₃Cl	Mon. 2/m
3.DA.10c	Paratacamite	Cu₃(Cu,Zn)(OH)₆Cl₂	Trig. 3 : R3
3.DA.10c	Kapellasite	Cu₃Zn(OH)₆Cl₂	Trig. 3m(32/m) : P3m1
3.DA.10c	Leverettite	Cu₃Co(OH)₆Cl₂	Trig. 3 : R3
3.DA.10a	Hibbingite	Fe²⁺₂(OH)₃Cl	Orth. mmm(2/m2/m2/m) : Pnma
3.DA.10c	Paratacamite-(Ni)	Cu₃(Ni,Cu)(OH)₆Cl₂	Trig. 3 : R3
3.DA.10a	Kempite	Mn²⁺₂(OH)₃Cl	Orth. mmm(2/m2/m2/m) : Pnma
3.DA.10c	Tondiite	Cu₃Mg(OH)₆Cl₂	Trig. 3m(32/m) : R3m
3.DA.10a	Atacamite	Cu₂(OH)₃Cl	Orth. mmm(2/m2/m2/m) : Pnma
3.DA.10b	Belloite	Cu(OH)Cl	Mon. 2/m : P2₁/b
3.DA.10c	Misakiite	Cu₃Mn(OH)₆Cl₂	Trig. 3m(32/m) : P3m1
3.DA.10b	Iyoite	MnCuCl(OH)₃	Mon. 2/m : P2₁/m
3.DA.10c	Kuliginite	Fe₃Mg(OH)₆Cl₂	Trig. 3 : R3
3.DA.10c	Gillardite	Cu₃Ni(OH)₆Cl₂	Trig. 3m(32/m) : R3m
3.DA.10b	'Unnamed (Cu-Zn Chloride Hydroxide)'	CuZnCl(OH)₃	Mon. 2/m : P2₁/m
3.DA.10b	Botallackite	Cu₂(OH)₃Cl	Mon. 2/m : P2₁/m
3.DA.10c	Herbertsmithite	Cu₃Zn(OH)₆Cl₂	Trig. 3m(32/m) : R3m
3.DA.15	Claringbullite	Cu₄ClF(OH)₆	Hex. 6/mmm(6/m2/m2/m) : P6₃/mmc
3.DA.15	Barlowite	Cu₄BrF(OH)₆	Hex. 6/mmm(6/m2/m2/m) : P6₃/mmc
3.DA.20	Simonkolleite	Zn₅Cl₂(OH)₈ · H₂O	Trig. 3m(32/m) : P3m1
3.DA.25	Buttgenbachite	Cu₁₉(NO₃)₂(OH)₃₂Cl₄ · 2H₂O	Hex. 6/mmm(6/m2/m2/m) : P6₃/mmc
3.DA.25	Connellite	Cu₁₉(SO₄)(OH)₃₂Cl₄ · 3H₂O	Hex. 6m2 : P6₂c
3.DA.30	Abhurite	Sn₂₁Cl₁₆(OH)₁₄O₆	Trig. 32 : R32
3.DA.35	Ponomarevite	K₄Cu₄Cl₁₀O	Mon. 2/m : B2/b
3.DA.40	Calumetite	CaCu₄(OH)₈Cl₂ · 3.5H₂O	Orth. mmm(2/m2/m2/m) : Cmcm
3.DA.40	Anthonyite	Cu(OH,Cl)₂ · 3H₂O	Mon. 2/m
3.DA.45	Khaidarkanite	Cu₄Al₃(OH)₁₄F₃ · 2H₂O	Mon. 2/m : B2/m
3.DA.50	Bobkingite	Cu₅Cl₂(OH)₈ · 2H₂O	Mon. 2/m : B2/m
3.DA.55	Avdoninite	K₂Cu₅(OH)₄Cl₈ · H₂O	Mon. 2/m : P2₁/b
3.DA.60	Droninoite	Ni₆Fe³⁺₂(OH)₁₆Cl₂ · 4H₂O	Trig. 3m(32/m) : R3m
3.DA.70	Chrysothallite	K₆Cu₆Tl³⁺Cl₁₇(OH)₄ · H₂O	Tet. 4/mmm(4/m2/m2/m) : I4/mmm
3.DA.75	Feodosiyite	Cu₁₁Mg₂Cl₁₈(OH)₈ · 16H₂O	Mon. 2/m : P2₁/b
3.DA.80	Romanorlovite	K₈Cu₆Cl₁₇(OH)₃	Tet. 4/mmm(4/m2/m2/m) : I4/mmm

Other InformationHide

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 DioskouriiteHide

mindat.org URL:

https://www.mindat.org/min-47598.html
Please feel free to link to this page.

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Raman and XRD data at RRUFF project

References and PDF downloads at RRUFF project

American Mineralogist Crystal Structure Database

Mineral Dealers:

The Arkenstone - Fine Minerals

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References for DioskouriiteHide

Reference List:

Hålenius, U., Hatert, F., Pasero, M., Mills, S.J. (2016) New minerals and nomenclature modifications approved in 2016, CNMNC Newsletter no 30. Mineralogical Magazine, 80 (2) 407-413 doi:10.1180/minmag.2016.080.081

(2016)

Localities for DioskouriiteHide

Showing 2 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the 👁 Image
symbol to view information about a locality. The 👁 Image
symbol next to localities in the list can be used to jump to that position on the map.

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Locality ListHide

👁 Image
- This locality has map coordinates listed. 👁 Image
- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. 👁 Image
- Good crystals or important locality for species. 👁 Image
- 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.

Russia (TL)

Kamchatka Krai

Milkovsky District

Tolbachik Volcanic field

Great Fissure eruption (Main Fracture)

Northern Breakthrough (North Breach)

Second scoria cone

ⓘ Arsenatnaya fumarole (TL)

Hålenius et al. (2016)

ⓘ Glavnaya Tenoritovaya fumarole (Major Tenorite)

Hålenius et al. (2016) +1 other reference

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⇱ Dioskouriite: Mineral information, data and localities.

Dioskouriite

About DioskouriiteHide