Pyradoketosite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
Formula:
Ag3SbS3
Colour:
Orange
Lustre:
Adamantine
Specific Gravity:
5.809 (Calculated)
Crystal System:
Monoclinic
Name:
The name is derived from the Greek words “πυρ” (fire) and “άδόκητος” (unforeseen) for the surprise at finding a new polymorph of the “ruby silvers”, pyrargyrite and pyrostilpnite, that have been known for a long time.
Type Locality:
Polymorph of:
A polymorph of Ag3SbS3 after pyrargyrite and pyrostilpnite.
Pyradoketosite is slightly less-densely packed (V = 154.8 Å3) with respect to pyrargyrite (V = 153.6 Å3) and pyrostilpnite (V = 152.1 Å3).
Crystal structure details:
* alternating {101} layers: an Sb-rich layer, Sb3AgS3, and two distinct Ag8S6 layers;
* structurally related with the wittichenite-skinnerite pair.
Pyradoketosite is slightly less-densely packed (V = 154.8 Å3) with respect to pyrargyrite (V = 153.6 Å3) and pyrostilpnite (V = 152.1 Å3).
Crystal structure details:
* alternating {101} layers: an Sb-rich layer, Sb3AgS3, and two distinct Ag8S6 layers;
* structurally related with the wittichenite-skinnerite pair.
Unique Identifiers
Mindat ID:
54571
Long-form identifier:
mindat:1:1:54571:2
GUID
(UUID V4):
(UUID V4):
8d72abe1-9223-4d72-9580-82a08f11168e
IMA Classification of Pyradoketosite
Classification of Pyradoketosite
2.GA.
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
G : Sulfarsenites, sulfantimonites, sulfbismuthites
A : Neso-sulfarsenites, etc. without additional S
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
G : Sulfarsenites, sulfantimonites, sulfbismuthites
A : Neso-sulfarsenites, etc. without additional S
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 |
|---|---|---|
| Pdk | 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 Pyradoketosite
Adamantine
Transparency:
Translucent
Colour:
Orange
Streak:
Orange
Hardness Data:
Could not be measured
Tenacity:
Brittle
Cleavage:
None Observed
Density:
5.809 g/cm3 (Calculated)
Comment:
Density could not be measured.
Optical Data of Pyradoketosite
Anisotropism:
Anisotropism was not observed, being masked by abundant internal reflections.
Bireflectance:
Weak
Reflectivity:
| Wavelength | R1 | R2 |
|---|---|---|
| 400nm | 36.0% | 36.9% |
| 420nm | 35.0% | 35.6% |
| 440nm | 34.0% | 34.3% |
| 460nm | 33.0% | 33.3% |
| 470nm | 32.8% | 32.9% |
| 480nm | 32.2% | 32.4% |
| 500nm | 30.9% | 31.9% |
| 520nm | 30.9% | 31.3% |
| 540nm | 30.4% | 30.8% |
| 546nm | 30.2% | 30.7% |
| 560nm | 29.8% | 30.3% |
| 580nm | 29.2% | 29.8% |
| 589nm | 29.0% | 29.6% |
| 600nm | 28.7% | 29.3% |
| 620nm | 28.3% | 29.0% |
| 640nm | 27.7% | 28.6% |
| 650nm | 27.5% | 28.4% |
| 660nm | 27.2% | 28.2% |
| 680nm | 26.9% | 28.0% |
| 700nm | 26.7% | 27.9% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 36.9%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Slightly bluish grey
Internal Reflections:
Orange, abundant
Pleochroism:
Non-pleochroic
Chemistry of Pyradoketosite
Mindat Formula:
Ag3SbS3
Elements listed:
Crystallography of Pyradoketosite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 13.7510(15) Å, b = 6.9350(6) Å, c = 19.555(2) Å
β = 94.807(4)°
β = 94.807(4)°
Ratio:
a:b:c = 1.983 : 1 : 2.82
Unit Cell V:
1,858.27 ų (Calculated from Unit Cell)
Z:
12
Morphology:
Acicular crystals, up to 200 micron in length. Striated parallel to the elongation.
Twinning:
None observed.
Comment:
Space group P21/n.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.4 Å | (w) |
| 3.381 Å | (mw) |
| 3.035 Å | (s) |
| 2.505 Å | (mw) |
| 2.441 Å | (mw) |
| 2.160 Å | (mw) |
| 1.912 Å | (mw) |
| 1.878 Å | (mw) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-𝑇 alteration and/or metamorphism | |
| 33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) |
Type Occurrence of Pyradoketosite
General Appearance of Type Material:
Acicular crystals, striated parallel to the elongation, up to 200 μm in length and 25 μm in thickness.
Place of Conservation of Type Material:
Type material is deposited in the mineralogical collections of the Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI), Italy, catalogue number 19913.
Empirical Formula of Type Material:
Ag2.996Sb1.004S2.996
Geological Setting of Type Material:
Ore deposit located close to the contact between a Paleozoic metasedimentary-metavolcanic sequence and Triassic metadolostone.
Associated Minerals at Type Locality:
Related Minerals - Strunz-mindat Grouping
| 2.GA. | Arsiccioite | AgHg2Tl(As,Sb)2S6 |
| 2.GA. | Eckerite | Ag2CuAsS3 |
| 2.GA.05 | Proustite | Ag3AsS3 |
| 2.GA.05 | Pyrargyrite | Ag3SbS3 |
| 2.GA.10 | Pyrostilpnite | Ag3SbS3 |
| 2.GA.10 | Xanthoconite | Ag3AsS3 |
| 2.GA.15 | Samsonite | Ag4MnSb2S6 |
| 2.GA.20 | Skinnerite | Cu3SbS3 |
| 2.GA.20 | Wittichenite | Cu3BiS3 |
| 2.GA.20 | Bytízite | Cu3SbSe3 |
| 2.GA.25 | Lapieite | NiCuSbS3 |
| 2.GA.25 | Mückeite | NiCu(Bi,Sb)S3 |
| 2.GA.25 | Malyshevite | PdCuBiS3 |
| 2.GA.25 | Lisiguangite | PtCuBiS3 |
| 2.GA.25 | Roterbärite | PdBiCuSe3 |
| 2.GA.30 | Aktashite | Cu6Hg3As4S12 |
| 2.GA.30 | Gruzdevite | Cu6Hg3Sb4S12 |
| 2.GA.30 | Nowackiite | Cu6Zn3As4S12 |
| 2.GA.30 | Zhengminghuaite | Cu6Fe3As4S12 |
| 2.GA.35 | Laffittite | AgHgAsS3 |
| 2.GA.40 | Routhierite | Tl(Cu,Ag)(Hg,Zn)2(As,Sb)2S6 |
| 2.GA.40 | Stalderite | Tl(Cu,Ag)(Zn,Fe,Hg)2(As,Sb)2S6 |
| 2.GA.40 | Ralphcannonite | AgZn2TlAs2S6 |
| 2.GA.40 | Ferrostalderite | CuFe2TlAs2S6 |
| 2.GA.40 | Unnamed (Ag-Fe endmember of Routhierite Group) | AgFe2TlAs2S6 |
| 2.GA.45 | Erniggliite | Tl2SnAs2S6 |
| 2.GA.50 | Bournonite | PbCuSbS3 |
| 2.GA.50 | Seligmannite | PbCuAsS3 |
| 2.GA.50 | Součekite | PbCuBi(S,Se)3 |
| 2.GA.50 | Unnamed (Pb-Cu-Bi Selenide) | PbCuBiSe3 |
| 2.GA.50 | Cerromojonite | CuPbBiSe3 |
| 2.GA.55 | Eldragónite | Cu6BiSe4(Se2) |
Other Information
Notes:
Weakly light sensitive.
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 Pyradoketosite
mindat.org URL:
https://www.mindat.org/min-54571.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 Pyradoketosite
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2020) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 55. European Journal of Mineralogy, 32 (3) 367-371 doi:10.5194/ejm-32-367-2020
Localities for Pyradoketosite
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.
Italy (TL) | |
| Miyawaki et al. (2020) +2 other references |
