Log In
Paramolybdomenite
A valid IMA mineral species - pending publication
This page is currently not sponsored. Click here to sponsor this page.
About Paramolybdomenite
Formula:
PbSeO3
Colour:
bright yellow
Lustre:
Adamantine
Specific Gravity:
6.743 (Calculated)
Crystal System:
Monoclinic
Name:
It was named paramolybdomenite (Cyrillic: парамолибдоменит) due to the dimorphism with molybdomenite, which name originates from the Greek μόλυβδος for "lead" and μήυη for "moon", because the chemical element selenium is named for the moon.
Type Locality:
Dimorph of:
Paramolybdomenite is a natural analogue of synthetic α-PbSeO3.
In the structure of paramolybdomenite the [Pb2+O9] polyhedra are cross-connected via common edges and are connected via common corners with [Se4+O3] groups to form a quasiframework. Selenium atoms occupy two crystallographically independent sites; the Se1 site is occupied only with Se4+, whereas Se2 has the mixed Se/S population [substitution of (SeO3)2–for (SO4)2–]
Paramolybdomenite is represented in nature, as it is known now, by two chemical varieties: S-enriched one, containing up to 6.4 wt.% SO3 (from the type locality: Tolbachik), and S-free, corresponding to the end-member (the second occurrence: El Dragón Mine).
In the structure of paramolybdomenite the [Pb2+O9] polyhedra are cross-connected via common edges and are connected via common corners with [Se4+O3] groups to form a quasiframework. Selenium atoms occupy two crystallographically independent sites; the Se1 site is occupied only with Se4+, whereas Se2 has the mixed Se/S population [substitution of (SeO3)2–for (SO4)2–]
Paramolybdomenite is represented in nature, as it is known now, by two chemical varieties: S-enriched one, containing up to 6.4 wt.% SO3 (from the type locality: Tolbachik), and S-free, corresponding to the end-member (the second occurrence: El Dragón Mine).
Unique Identifiers
Mindat ID:
470834
Long-form identifier:
mindat:1:1:470834:2
IMA Classification of Paramolybdomenite
Approved, Pending publication
IMA Formula:
Pb2+Se4+O3
Approval year:
2023
Approval history:
IMA No. 2023-025
Type description reference:
Classification of Paramolybdomenite
4.JF.
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
F : Selenites without additional anions, without H2O
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
F : Selenites without additional anions, without H2O
Mineral Symbols
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 |
|---|---|---|
| Pmdm | 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 Paramolybdomenite
Adamantine
Transparency:
Transparent
Colour:
Bright yellow
Streak:
Yellowish
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
none
Fracture:
Irregular/Uneven
Density:
6.743 g/cm3 (Calculated)
Chemistry of Paramolybdomenite
Mindat Formula:
PbSeO3
Element Weights:
Elements listed:
Common Impurities:
S
Crystallography of Paramolybdomenite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/c
Setting:
P21/c
Cell Parameters:
a = 8.997(1) Å, b = 8.159(1) Å, c = 9.032(1) Å
β = 103.33(1)°
β = 103.33(1)°
Ratio:
a:b:c = 1.103 : 1 : 1.107
Unit Cell V:
645.15 ų (Calculated from Unit Cell)
Z:
8
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.823 Å | (17) |
| 3.534 Å | (34) |
| 3.293 Å | (100) |
| 3.244 Å | (63) |
| 2.997 Å | (35) |
| 2.981 Å | (36) |
| 2.788 Å | (49) |
| 2.760 Å | (26) |
Reference:
Type Occurrence of Paramolybdomenite
General Appearance of Type Material:
tabular to lamellar crystals up to 0.1 × 0.05 × 0.01 mm and their clusters up to 0.15 mm
The crystals demonstrate different signs of the skeletal growth: they are surrounded by fringed aggregates of acicular or columnar tiny subindividuals grown on lateral faces and are typically cavernous, "waffle-like"
The crystals demonstrate different signs of the skeletal growth: they are surrounded by fringed aggregates of acicular or columnar tiny subindividuals grown on lateral faces and are typically cavernous, "waffle-like"
Place of Conservation of Type Material:
collections of the Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18-2, Moscow 119071, Russia, registration number 6007/1
Geological Setting of Type Material:
it is a supergene mineral formed in the weathering zone of the deposits of volcanic fumaroles extinct for a long time.
Associated Minerals at Type Locality:
Reference:
Other Language Names for Paramolybdomenite
Dutch:Paramolybdomeniet
German:Paramolybdomenit
Related Minerals - Strunz-mindat Grouping
| 4.JF.05 | Molybdomenite | PbSeO3 |
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 Paramolybdomenite
mindat.org URL:
https://www.mindat.org/min-470834.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Paramolybdomenite
Reference List:
Bosi, Ferdinando; Hatert, Frédéric; Pasero, Marco; Mills, Stuart J. (2023) Newsletter 74. Mineralogical Magazine, 87 (5). 783-787 doi:10.1180/mgm.2023.54
Zhang, Jingnan; Yang, Hexiong; Gibbs, Ronald B. (2024) Molybdomenite-P21/c, Polymorphous with Molybdomenite and the Natural Analogue of Synthetic α-PbSe4+O3, from the El Dragón Mine, Potosí, Bolivia. The Canadian Journal of Mineralogy and Petrology, 62 (4). 643-652 doi:10.3749/2400004(as "Molybdomenite-P21/c")
Localities for Paramolybdomenite
Showing 2 localities.
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.
Bolivia | |
| Pekov et al. (2025) |
Russia (TL) | |
| Bosi et al. (2023) +2 other references |
Western paleo-fumarole field, Mountain 1004, Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia