Ferrofettelite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Ferrofettelite
Formula:
[Ag6As2S7][Ag10FeAs2S8]
Lustre:
Metallic
Specific Gravity:
5.74 (Calculated)
Crystal System:
Monoclinic
Name:
The mineral is the Fe-dominant analogue of fettelite.
The Fe analogue of fettelite. Chemically related to kenoargentotennantite-(Fe) and 'Unnamed (Fe-analogue of Argentotennantite-(Zn))'.
Unique Identifiers
Mindat ID:
55764
Long-form identifier:
mindat:1:1:55764:7
IMA Classification of Ferrofettelite
Classification of Ferrofettelite
2.LA.
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
L : Unclassified Sulfosalts
A : Without essential Pb
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
L : Unclassified Sulfosalts
A : Without essential Pb
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 |
|---|---|---|
| Fftt | 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 Ferrofettelite
Metallic
Transparency:
Opaque
Streak:
Dark reddish-gray
Hardness:
VHN20=122 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
5.74 g/cm3 (Calculated)
Optical Data of Ferrofettelite
Anisotropism:
Weak
Bireflectance:
White to brownish grey
Reflectivity:
| Wavelength | R1 (%) | R2 (%) |
|---|---|---|
| 471nm | 28.2% | 29.4% |
| 548nm | 25.0% | 26.3% |
| 586nm | 22.9% | 23.5% |
| 652nm | 20.9% | 21.2% |
Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 29.4%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Greyish white
Internal Reflections:
Red
Chemistry of Ferrofettelite
Mindat Formula:
[Ag6As2S7][Ag10FeAs2S8]
Element Weights:
Elements listed:
Crystallography of Ferrofettelite
Crystal System:
Monoclinic
Class (H-M):
2 - Sphenoidal
Space Group:
B2
Setting:
C2
Cell Parameters:
a = 26.011(2) Å, b = 15.048(1) Å, c = 15.513(1) Å
β = 90.40(1)°
β = 90.40(1)°
Ratio:
a:b:c = 1.729 : 1 : 1.031
Unit Cell V:
6,071.85 ų (Calculated from Unit Cell)
Z:
8
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.18 Å | (50) |
| 3.014 Å | (100) |
| 3.004 Å | (60) |
| 2.930 Å | (15) |
| 2.755 Å | (40) |
| 2.501 Å | (30) |
| 2.484 Å | (20) |
| 1.880 Å | (30) |
Type Occurrence of Ferrofettelite
General Appearance of Type Material:
Anhedral to subhedral flakes and grains up to 80 μm.
Place of Conservation of Type Material:
Collections of the University of Arizona Gem and Mineral Museum, 115 N Church Ave., Tucson, AZ 85701, USA, catalogue number 22716.
Associated Minerals at Type Locality:
Synonyms of Ferrofettelite
Other Language Names for Ferrofettelite
Dutch:Ferrofetteliet
German:Ferrofettelit
Related Minerals - Strunz-mindat Grouping
| 2.LA. | Thunderbayite | TlAg3Au3Sb7S6 |
| 2.LA. | Auerbakhite | MnTl2As2S5 |
| 2.LA. | Biagioniite | Tl2SbS2 |
| 2.LA. | Gladkovskyite | MnTlAs3S6 |
| 2.LA.10 | Dervillite | Ag2AsS2 |
| 2.LA.15 | Daomanite | CuPtAsS2 |
| 2.LA.20 | Vaughanite | TlHgSb4S7 |
| 2.LA.25 | Criddleite | TlAg2Au3Sb10S10 |
| 2.LA.30 | Fettelite | [Ag6As2S7][Ag10HgAs2S8] |
| 2.LA.35 | Chaméanite | (Cu,Fe)4As(Se,S)4 |
| 2.LA.40 | Arcubisite | Ag6CuBiS4 |
| 2.LA.45 | Mgriite | Cu3AsSe3 |
| 2.LA.50 | Benleonardite | [Ag6(Sb,As)2S6Te][Ag9Cu(S,Te)2Te2] |
| 2.LA.55 | Tsnigriite | Ag9SbTe3S3 |
| 2.LA.60 | Borovskite | Pd3SbTe4 |
| 2.LA.65 | Jonassonite | AuBi5S4 |
| 2.LA.65 | Nuwaite | Ni6GeS2 |
| 2.LA.65 | Butianite | Ni6SnS2 |
| 2.LA.70 | Raberite | Tl5Ag4As6SbS15 |
| 2.LA.75 | Spaltiite | Tl2Cu2As2S5 |
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 Ferrofettelite
mindat.org URL:
https://www.mindat.org/min-55764.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 Ferrofettelite
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 65. European Journal of Mineralogy, 34 (1) 143-148 doi:10.5194/ejm-34-143-2022
Localities for Ferrofettelite
Showing 1 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.
Germany (TL) | |
| Bindi et al. (2022) +1 other reference |
Quick NavTopAbout FerrofetteliteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionType Occurrence SynonymsOther LanguagesStrunz-MindatOther InformationInternet Links References Localities Locality List
Glasberg quarry, Nieder-Beerbach, Mühltal, Darmstadt-Dieburg, Darmstadt, Hesse, Germany