Grootfonteinite
A valid IMA mineral species
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About Grootfonteinite
Formula:
Pb3O(CO3)2
Colour:
Colorless
Lustre:
Adamantine
Hardness:
2
Specific Gravity:
6.856 (Calculated)
Crystal System:
Hexagonal
Name:
Named after the Grootfontein district, that includes the type locality.
Structurally related to hydrocerussite and plumbonacrite. Chemically related to shannonite and UM1995-03-CO:Pb.
Unique Identifiers
Mindat ID:
46809
Long-form identifier:
mindat:1:1:46809:7
GUID
(UUID V4):
(UUID V4):
292b2e90-655a-4722-b354-690ba751dfe6
IMA Classification of Grootfonteinite
Approved
Approval year:
2015
First published:
2018
Type description reference:
Siidra, Oleg I., Jonsson, Erik, Chukanov, Nikita V., Nekrasova, Diana O., Pekov, Igor V., Depmeier, Wulf, Polekhovsky, Yury S., Yapaskurt, Vasiliy O. (2018) Grootfonteinite, Pb3O(CO3)2, a new mineral species from the Kombat Mine, Namibia, merotypically related to hydrocerussite. European Journal of Mineralogy, 30 (2) 383-391 doi:10.1127/ejm/2018/0030-2723
Classification of Grootfonteinite
5.BE.40
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
E : With Pb, Bi
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
E : With Pb, Bi
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 |
|---|---|---|
| Gtf | 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 Grootfonteinite
Adamantine
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
2 on Mohs scale
Hardness:
VHN20=48.7 - 66.1 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
Perfect
(0 0 1)
(0 0 1)
Parting:
Not observed
Fracture:
Irregular/Uneven
Density:
6.856 g/cm3 (Calculated)
Comment:
Could not be measured
Optical Data of Grootfonteinite
Anisotropism:
Weak, ΔR(589nm)=2.1%, masked by internal reflections
Bireflectance:
Very weak
Reflectivity:
| Wavelength | R1 | R2 |
|---|---|---|
| 400nm | 11.7% | 13.9% |
| 420nm | 11.4% | 13.6% |
| 440nm | 11.1% | 13.3% |
| 460nm | 10.9% | 13.1% |
| 470nm | 10.8% | 13.0% |
| 480nm | 10.7% | 12.9% |
| 500nm | 10.6% | 12.8% |
| 520nm | 10.5% | 12.7% |
| 540nm | 10.5% | 12.6% |
| 546nm | 10.5% | 12.6% |
| 560nm | 10.4% | 12.6% |
| 580nm | 10.4% | 12.5% |
| 589nm | 10.3% | 12.5% |
| 600nm | 10.3% | 12.4% |
| 620nm | 10.3% | 12.4% |
| 640nm | 10.2% | 12.3% |
| 650nm | 10.2% | 12.3% |
| 660nm | 10.2% | 12.2% |
| 680nm | 10.2% | 12.2% |
| 700nm | 10.2% | 12.1% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 13.9%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Grey
Internal Reflections:
White
Pleochroism:
Non-pleochroic
Chemistry of Grootfonteinite
Mindat Formula:
Pb3O(CO3)2
Elements listed:
Crystallography of Grootfonteinite
Crystal System:
Hexagonal
Class (H-M):
6mm - Dihexagonal Pyramidal
Space Group:
P63mc
Cell Parameters:
a = 5.303(1) Å, c = 13.770(2) Å
Ratio:
a:c = 1 : 2.597
Unit Cell V:
334.88 ų
Z:
2
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.353 Å | (9) |
| 3.441 Å | (8) |
| 3.244 Å | (100) |
| 2.652 Å | (30) |
| 2.627 Å | (12) |
| 2.294 Å | (21) |
| 2.267 Å | (5) |
| 2.053 Å | (39) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Type Occurrence of Grootfonteinite
General Appearance of Type Material:
Platy grains up to 1 mm across and up to 0.2 mm thick.
Place of Conservation of Type Material:
Cotype material is deposited in the mineralogical collections of the Swedish Museum of Natural History, Stockholm, Sweden, catalogue number 20080176.
Geological Setting of Type Material:
Complex, banded assemblage from a Mn(-Fe) oxide ore unit. May have formed by regional metamorphism of a primary, Pb-Mn-(As-Ba)-rich, chemically heterogeneous, volcanic-hydrothermal assemblage.
Associated Minerals at Type Locality:
Reference:
Siidra, O.I., Jonsson, E., Chukanov, N.V., Nekrasova, D.O., Pekov, I.V., Depmeier, W., Polekhovsky, Y.S., Yapaskurt, V.O. (2018) Grootfonteinite, Pb3O(CO3)2, a new mineral species from the Kombat Mine, Namibia, merotypically related to hydrocerussite. European Journal of Mineralogy: 30(2): 383-391.
Synonyms of Grootfonteinite
Common Associates
Associated Minerals Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 5.BE.X | Abellaite | NaPb2(CO3)2(OH) |
| 5.BE.05 | Shannonite | Pb2O(CO3) |
| 5.BE.10 | Hydrocerussite | Pb3(CO3)2(OH)2 |
| 5.BE.15 | Plumbonacrite | Pb5O(OH)2(CO3)3 |
| 5.BE.20 | Phosgenite | Pb2CO3Cl2 |
| 5.BE.25 | Bismutite | (BiO)2CO3 |
| 5.BE.30 | Kettnerite | CaBiCO3OF |
| 5.BE.35 | Beyerite | Ca(BiO)2(CO3)2 |
| 5.BE.45 | Somersetite | Pb8O2(OH)2(CO3)5 |
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 Grootfonteinite
mindat.org URL:
https://www.mindat.org/min-46809.html
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External Links:
Mineral Dealers:
References for Grootfonteinite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2015) New minerals and nomenclature modifications approved in 2015, CNMNC Newsletter No 27. Mineralogical Magazine, 79 (5) 1223-1230 doi:10.1180/minmag.2015.079.5.16
Siidra, Oleg I., Jonsson, Erik, Chukanov, Nikita V., Nekrasova, Diana O., Pekov, Igor V., Depmeier, Wulf, Polekhovsky, Yury S., Yapaskurt, Vasiliy O. (2018) Grootfonteinite, Pb3O(CO3)2, a new mineral species from the Kombat Mine, Namibia, merotypically related to hydrocerussite. European Journal of Mineralogy, 30 (2) 383-391 doi:10.1127/ejm/2018/0030-2723
Siidra, Oleg, Nekrasova, Diana, Depmeier, Wulf, Chukanov, Nikita, Zaitsev, Anatoly, Turner, Rick (2018) Hydrocerussite-related minerals and materials: structural principles, chemical variations and infrared spectroscopy. Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials, 74 (2). 182-195 doi:10.1107/s2052520618000768
Localities for Grootfonteinite
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.
Namibia (TL) | |
| Hålenius et al. (2015) +1 other reference |
Quick NavTopAbout GrootfonteiniteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Kombat Mine, Kombat, Otavi Constituency, Otjozondjupa Region, Namibia