Furutobeite
A valid IMA mineral species
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About Furutobeite
Formula:
(Cu,Ag)6PbS4
Colour:
Gray
Lustre:
Metallic
Hardness:
3
Specific Gravity:
6.74 (Calculated)
Crystal System:
Monoclinic
Name:
Named after the Furutobe mine, Japan, the discovery locality.
This page provides mineralogical data about Furutobeite.
Unique Identifiers
Mindat ID:
1622
Long-form identifier:
mindat:1:1:1622:9
IMA Classification of Furutobeite
Approved
IMA Formula:
(Cu1+,Ag1+)6Pb2+S2-4
Approval year:
1978
First published:
1981
Classification of Furutobeite
2.BE.10
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
E : With Pb (Bi)
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
E : With Pb (Bi)
2.16.12.1
2 : SULFIDES
16 : Miscellaneous
2 : SULFIDES
16 : Miscellaneous
3.6.8
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
6 : Sulphides etc. of Sb and Pb
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
6 : Sulphides etc. of Sb and Pb
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 |
|---|---|---|
| Fur | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Fur | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Furutobeite
Metallic
Transparency:
Opaque
Colour:
Gray
Hardness:
3 on Mohs scale
Hardness:
VHN25=100 - 108 kg/mm2 - Vickers
Density:
6.74 g/cm3 (Calculated)
Optical Data of Furutobeite
Anisotropism:
Moderate from light yellow to dark brown
Reflectivity:
| Wavelength | R1 (%) | R2 (%) |
|---|---|---|
| 480nm | 32.0% | 34.6% |
| 546nm | 32.8% | 34.9% |
| 589nm | 33.2% | 35.2% |
| 657nm | 33.6% | 34.6% |
Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 35.2%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Gray with a creamy yellow tint
Pleochroism:
Weak
Chemistry of Furutobeite
Mindat Formula:
(Cu,Ag)6PbS4
Element Weights:
Elements listed:
Crystallography of Furutobeite
Crystal System:
Monoclinic
Cell Parameters:
a = 20.02 Å, b = 3.96 Å, c = 9.07 Å
β = 101.57°
β = 101.57°
Ratio:
a:b:c = 5.056 : 1 : 2.29
Unit Cell V:
704.45 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Granular to 300 microns
Comment:
Point Group: m, 2, or 2/m; Space Group: Cm, C2, or C2/m.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.43 Å | (50) |
| 2.95 Å | (90) |
| 2.61 Å | (50) |
| 2.55 Å | (70) |
| 2.50 Å | (100) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) |
Type Occurrence of Furutobeite
General Appearance of Type Material:
Grains 10-300 microns
Place of Conservation of Type Material:
Institute of Mineralogy, Petrology and Economic Geology, Faculty of Science, Tohoku University, Sendai, Japan
Geological Setting of Type Material:
Kuroko deposit
Associated Minerals at Type Locality:
Synonyms of Furutobeite
Other Language Names for Furutobeite
Common Associates
Associations Based on Photo Data:
| 11 photos of Furutobeite associated with Quartz | SiO2 |
| 5 photos of Furutobeite associated with Galena | PbS |
| 4 photos of Furutobeite associated with Acanthite | Ag2S |
| 4 photos of Furutobeite associated with Native Silver | Ag |
| 3 photos of Furutobeite associated with Pyrite | FeS2 |
| 2 photos of Furutobeite associated with Calcite | CaCO3 |
| 2 photos of Furutobeite associated with Tennantite Subgroup | Cu6(Cu4C2+2)As4S12S |
Related Minerals - Strunz-mindat Grouping
| 2.BE. | Dulanggouite | Bi6Te3 |
| 2.BE. | Zipserite | Bi5S4 |
| 2.BE.05 | Betekhtinite | Pb2(Cu,Fe)22-24S15 |
| 2.BE.15 | Shandite | Ni3Pb2S2 |
| 2.BE.15 | Rhodplumsite | Rh3Pb2S2 |
| 2.BE.20 | Parkerite | Ni3(Bi,Pb)2S2 |
| 2.BE.25 | Schlemaite | (Cu,◻)6(Pb,Bi)Se4 |
| 2.BE.30 | Pašavaite | Pd3Pb2Te2 |
Other Information
Thermal Behaviour:
When heated, it decomposes at 100+/-2°C into galena plus a solid solution of CuAgS and Cu2S, which when cooled forms stromeyerite and chalcocite.
Notes:
Etched iridescent by 20% FeCl3 solution and is blackened instantly by 20% KCN solution. Negative to KOH, HCl 1:1, HNO3 1:1 and HgCl2 solution.
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 Furutobeite
mindat.org URL:
https://www.mindat.org/min-1622.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Furutobeite
Localities for Furutobeite
Showing 11 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.
Austria | |
| Paar et al. (1985) +1 other reference |
China | |
| Chen et al. (2023) |
Czech Republic | |
| Fojt et al. (2010) |
Egypt | |
| Sallam et al. (2014) |
Japan (TL) | |
| Sugaki et al. (1981) +1 other reference |
| Bernstein (1986) |
Namibia | |
| Mineralogical Society of America - ... |
Russia | |
| Kovalev et al. (2017) |
USA | |
| Schumer (2017) |
| Gammons et al. (2016) |
| Species confirmed by Dr. Ben Schumer of ... |
Quick NavTopAbout FurutobeiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Tsumeb Mine, Tsumeb, Oshikoto Region, Namibia