Ermakovite (original) (raw)

A valid IMA mineral species

About ErmakoviteHide

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Name:

Named in honor of Nikolai Porfirievich Ermakov (Николай Порфирьевич Ермаков) (16 November 1913, Kondurchinskaya fortress, Samara province, Russia - 25 September 1993, Moscow , Russia), professor of mineralogy, head of the thermobarogeochemistry lab and founder of the Earth Science Museum at Moscow State University (Russia).

The Br analogue of mauriziodiniite. Known synthetic analogue.

Additional associate: amorphous As2S3.

Details of the sandwich-type structure that has three types of layers
(1) a honeycomb [As2O3] arsenite layer
(2) an NH4+ layer
(3) a Br-layer;
The layer stacking sequence is NH4-As2O3-Br-As2O3-NH4.

Also compare lucabindiite, torrecillasite, and russoite.

Unique IdentifiersHide

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Long-form identifier:

mindat:1:1:55233:2

8b8eec8d-5b00-4c8a-8bb8-0289d67e34ba

IMA Classification of ErmakoviteHide

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Type description reference:

Karpenko, Vladimir Yu., Pautov, Leonid A., Siidra, Oleg I., Mirakov, Mirak A., Zaitsev, Anatoly N., Plechov, Pavel Yu., Makhmadsharif, Saimudasir (2023) Ermakovite (NH4)(As2O3)2Br, a new exhalative arsenite bromide mineral from the Fan-Yagnob coal deposit, Tajikistan. Mineralogical Magazine, 87 (1) 69-78 doi:10.1180/mgm.2022.116

Classification of ErmakoviteHide

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3.C0.

3 : HALIDES
C : Complex halides
0 :

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.

Physical Properties of ErmakoviteHide

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Comment:

Zoned with a transparent yellowish core and semi-transparent yellow rim.

Streak:

White with a yellowish tint

Hardness:

VHN20=40 kg/mm2 - Vickers

Fracture:

Irregular/Uneven

Density:

3.64(2) g/cm3 (Measured) 3.747 g/cm3 (Calculated)

Optical Data of ErmakoviteHide

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RI values:

_n_ω = 1.960(5) _n_ε = 1.716(3)

δ = 0.244

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.

Pleochroism:

Non-pleochroic

Chemistry of ErmakoviteHide

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Mindat Formula:

(NH4)(As2O3)2Br

Crystallography of ErmakoviteHide

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Class (H-M):

6/m m m _(_6/_m_2/_m_2/m ) - Dihexagonal Dipyramidal

Cell Parameters:

a = 5.271(3) Å, c = 9.157(6) Å

Unit Cell V:

220.33 ų (Calculated from Unit Cell)

Morphology:

Tabular or prismatic, hexagonal crystals, up to 200 μm, with the c (001), m (010), and p (014) forms; commonly as spherolitic and multi-twinned intergrowths.

Twinning:

Multi-twinned intergrowths.

X-Ray Powder DiffractionHide

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Powder Diffraction Data:

Comments:

From Type Description.

Type Occurrence of ErmakoviteHide

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General Appearance of Type Material:

Tabular or prismatic, hexagonal crystals, up to 200 μm, with the c (001), m (010), and p (014) forms; commonly as spherolitic and multi-twinned intergrowths.

Place of Conservation of Type Material:

Type material is deposited in the collections of the Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18-2, Moscow 119071, Russia, registration number 5525/1.

Empirical Formula of Type Material:

[(NH4)0.92Na0.01]0.93(As3.94Sb0.06)4.00O6.02(Br0.97Cl0.08I0.01)1.06

Geological Setting of Type Material:

Coal-fire-driven exhalative processes within a fumarole.

Associated Minerals at Type Locality:

Synonyms of ErmakoviteHide

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Relationship of Ermakovite 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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Notes:

Insoluble in water, HCl, HNO3 or organic solvents.

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 ErmakoviteHide

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References for ErmakoviteHide

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Reference List:

Karpenko, Vladimir Yu., Pautov, Leonid A., Siidra, Oleg I., Mirakov, Mirak A., Zaitsev, Anatoly N., Plechov, Pavel Yu., Makhmadsharif, Saimudasir (2023) Ermakovite (NH4)(As2O3)2Br, a new exhalative arsenite bromide mineral from the Fan-Yagnob coal deposit, Tajikistan. Mineralogical Magazine, 87 (1) 69-78 doi:10.1180/mgm.2022.116

Localities for ErmakoviteHide

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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.