Pararealgar
A valid IMA mineral species
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About Pararealgar
Formula:
As4S4
Colour:
Light yellow to orange-brown
Lustre:
Vitreous, Resinous
Hardness:
1 - 1½
Specific Gravity:
3.52
Crystal System:
Monoclinic
Name:
Named in 1980 by Andrew C. Roberts, H. Gary Ansell, and Maurizio Bonardi from the Greek παρα "para" = beyond for the polymorphous structural relationship to realgar.
Red realgar alters to yellow/yellow-orange pararealgar on exposure to light.
Primary pararealgar is, however, also known.
Primary pararealgar is, however, also known.
Unique Identifiers
Mindat ID:
3107
Long-form identifier:
mindat:1:1:3107:9
IMA Classification of Pararealgar
Approved
IMA Formula:
AsS
Approval year:
1980
First published:
1980
Classification of Pararealgar
2.FA.15b
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
A : With As, (Sb), S
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
A : With As, (Sb), S
2.8.21.2
2 : SULFIDES
8 : AmXp, with m:p = 1:1
2 : SULFIDES
8 : AmXp, with m:p = 1:1
3.7.5
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
7 : Sulphides etc. of V, As, Sb and Bi
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
7 : Sulphides etc. of V, As, Sb and 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 for Standard |
|---|---|---|
| Prlg | 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 Pararealgar
Vitreous, Resinous
Transparency:
Translucent, Opaque
Colour:
Light yellow to orange-brown
Streak:
Light yellow
Hardness:
1 - 1½ on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
3.52(5) g/cm3 (Measured)
Optical Data of Pararealgar
Anisotropism:
Distinct
Internal Reflections:
Gold to orange-red
Pleochroism:
Strong
Comments:
Refractive indices could not be measured but are greater than 2.02.
Chemistry of Pararealgar
Mindat Formula:
As4S4
Elements listed:
Crystallography of Pararealgar
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/c
Cell Parameters:
a = 9.909 Å, b = 9.655 Å, c = 8.502 Å
β = 97.20°
β = 97.20°
Ratio:
a:b:c = 1.026 : 1 : 0.881
Unit Cell V:
806.8 ų
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0015782 | Pararealgar | Kutoglu A (1976) Darstellung und kristallstruktur einer neuen isomeren form von As4S4 Zeitschrift fur Anorganische und Allgemeine Chemie 419 176-184 | 1976 | synthetic | 0 | 293 | |
| 0001734 | Pararealgar | Bonazzi P, Menchetti S, Pratesi G (1995) The crystal structure of pararealgar American Mineralogist 80 400-403 |  | 1995 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.14 Å | (100) |
| 5.56 Å | (91) |
| 3.75 Å | (78) |
| 2.795 Å | (71) |
| 3.025 Å | (51) |
| 3.299 Å | (50) |
| 3.105 Å | (33) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 11 : Volcanic fumarole minerals; reduced phases (see also #45) | |
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 12 : Hadean hydrothermal subsurface sulfide deposits (see also #33) | |
| Near-surface Processes | |
| 28 : Photo-alteration, pre-biotic | |
| High-? alteration and/or metamorphism | |
| 33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Type Occurrence of Pararealgar
Co-Type Localities:
General Appearance of Type Material:
Powdery to granular fine-grained aggregates that replace realgar.
Place of Conservation of Type Material:
National Mineral Collection, Geological Survey of Canada, under catalogue numbers 61566 (Mount Washington) and 61567 (Gray Rock).
Associated Minerals at Type Locality:
Synonyms of Pararealgar
Other Language Names for Pararealgar
Common Associates
Associations Based on Photo Data:
| 127 photos of Pararealgar associated with Realgar | As4S4 |
| 22 photos of Pararealgar associated with Colemanite | Ca[B3O4(OH)3] · H2O |
| 21 photos of Pararealgar associated with Dolomite | CaMg(CO3)2 |
| 19 photos of Pararealgar associated with Orpiment | As2S3 |
| 17 photos of Pararealgar associated with Calcite | CaCO3 |
| 15 photos of Pararealgar associated with Quartz | SiO2 |
| 13 photos of Pararealgar associated with Native Arsenic | As |
| 13 photos of Pararealgar associated with Pyrite | FeS2 |
| 6 photos of Pararealgar associated with 'Agate' | SiO2 |
| 5 photos of Pararealgar associated with Wallisite | (Cu,Ag)TlPbAs2S5 |
Related Minerals - Strunz-mindat Grouping
| 2.FA. | Bonazziite | As4S4 |
| 2.FA. | Anorpiment | As2S3 |
| 2.FA. | Paradimorphite | As4S3 |
| 2.FA.05 | Duranusite | As4S |
| 2.FA.10 | Dimorphite | As4S3 |
| 2.FA.15a | Realgar | As4S4 |
| 2.FA.15d | 'UM1970-18-S:As' | As4S4 |
| 2.FA.20 | Alacránite | As8S9 |
| 2.FA.25 | Uzonite | As4S5 |
| 2.FA.30 | Laphamite | As2Se3 |
| 2.FA.30 | Orpiment | As2S3 |
| 2.FA.35 | Getchellite | AsSbS3 |
| 2.FA.40 | Wakabayashilite | [(As,Sb)6S9][As4S5] |
| 2.FA.40 | Kalgoorlieite | As2Te3 |
Fluorescence of Pararealgar
Not fluorescent.
Other Information
Notes:
Insoluble in cold or hot water, concentrated HCl, H2SO4 or HNO3, but reacts instantly in 40% KOH solution, forming a dark brown powdery precipitate.
Health Risks:
Contains arsenic - always wash hands after handling. Avoid inhaling dust when handling or breaking. Never lick or ingest.
Internet Links for Pararealgar
mindat.org URL:
https://www.mindat.org/min-3107.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 Pararealgar
Reference List:
Roberts, A. C., Ansell, H. G., Bonardi, M. (1980) Pararealgar, a new polymorph of AsS, from British Columbia. The Canadian Mineralogist, 18 (3) 525-527
Bonazzi, Paola, Menchetti, Silvio, Pratesi, Giovanni (1995) The crystal structure of pararealgar, As4S4. American Mineralogist, 80 (3) 400-403 doi:10.2138/am-1995-3-422
Kyono, A. (2005) Light-induced degradation dynamics in realgar: in situ structural investigation using single-crystal X-ray diffraction study and X-ray photoelectron spectroscopy. American Mineralogist, 90 (10) 1563-1570 doi:10.2138/am.2005.1785
Localities for Pararealgar
Showing 82 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.
Albania | |
| Jonas Mishra collection |
Austria | |
| Schnorrer (2000) |
| Niedermayr et al. (1995) |
| Auer (2022) |
| C.Auer (2005) |
| Christian Auer | |
| - (1994, July) |
Bolivia | |
| Bentz et al. (2017) |
Canada | |
| Roberts et al. (1980) +1 other reference |
| Roberts et al. (1980) +2 other references |
| Roberts et al. (1980) +1 other reference |
| Harris (1989) |
| Sabina (1991) | |
China | |
| Shen (n.d.) |
Costa Rica | |
| Paolo Bosio collection |
Czech Republic | |
| Hloušek et al. (2002) |
| Dr. Jan Hlousek label | |
France | |
| Frank Keutsch collection (originally via Fred Kennedy collection) |
| Mari et al. (2012) |
| Bourgoin et al. (2011) |
Germany | |
| Gröbner et al. (2005) |
| Walenta (1987) +1 other reference |
| |
| |
| Schwarzmeier et al. (2015) +2 other references |
| |
| Gefunden 1993 von M. Groß. Analyse Dr. Johanneas Heider Sangerhausen/Harz (Raman) | |
| Vollstädt et al. (1991) |
| Thalheim +1 other reference |
| |
| Witzke et al. (1998) |
Greece | |
| Rieck et al. (2020) |
| Rieck et al. (2020) |
Indonesia | |
| Collection of Alex Earl |
Italy | |
| Massimo (2004) |
| Russo et al. (2017) | |
| Bedognè et al. (1993) |
| - (n.d.) +2 other references |
| Nannoni et al. (2008) +1 other reference |
| Nannoni et al. (2008) +1 other reference | |
| Bonifazi (2021) |
| D'Achiardi (1899) +3 other references |
| D’Achiardi (1905) +1 other reference |
| D’Achiardi (1905) +2 other references | |
| Giordano (2008) |
Japan | |
| Matsubara et al. (2005) +1 other reference |
New Zealand | |
| Rod Martin personal collection |
North Macedonia | |
| Rieck (1993) +2 other references |
| Kolitsch et al. (2018) |
Peru | |
| Hyrsl et al. (2006) +2 other references |
Romania | |
| Szakáll et al. (Eds.) |
| Ed.:Szakáll S.-Kristály ... |
| Dion Glastra specimen |
| Minerals of Carpathians | |
| Koller G.2009 |
Russia | |
| - (n.d.) |
| Kasatkin et al. (2021) |
Slovakia | |
| Ďuďa R. |
| Duda |
Spain | |
| A Borrelli collection |
Switzerland | |
| Romani (2000) +1 other reference |
| Bedognè et al. (2006) | |
| Stalder et al. (1998) |
| 50. (in German) +1 other reference | |
Taiwan | |
| |
Turkey | |
| Erik Vercammen collection | |
| Erik Vercammen collection and field observations (1988) | |
UK | |
| Cotterell et al. (2011) |
USA | |
| www.mineralsocal.org (1999) |
| Morgan et al. (1969) +1 other reference |
| Newmont Mining Corporation |
| Barrick Gold Corporation | |
| Mineralogical Society of America - ... +1 other reference |
| Mineralogical Society of America - ... +1 other reference |
| Bowell et al. (2005) | |
| Walstrom (n.d.) +1 other reference |
| Excalibur mineral list CATALOG 21001 - ... |
| J. Cianciulli |
| Rod Martin Collection |
| Microprobe |
| NEEDS REFERENCE |
| Communication with Bart Cannon |
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Jas Roux, La Chapelle-en-Valgaudemar, Gap, Hautes-Alpes, Provence-Alpes-Côte d'Azur, France