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Pyroaurite-2H
A structural variant of Pyroaurite
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About Pyroaurite-2H
Formula:
Mg6Fe3+2(OH)16(CO3) · 4H2O
Colour:
White, yellowish green, brownish green, yellowish white, brownish white
Lustre:
Vitreous, Waxy, Pearly
Hardness:
2½
Specific Gravity:
2.08 - 2.14
Crystal System:
Hexagonal
Name:
Named for the structural relationship to pyroaurite. Originally named sjögrenite by Clifford Frondel in 1940 in honor of Stens Anders Hjalmar Sjögren (1856-1922), Professor of Mineralogy, University of Stockholm, Sweden.
First Recorded Locality:
A polytype of Pyroaurite
Originally named sjögrenite. Subsequently recognised as a polytype of pyroaurite and accordingly discredited as a species (Mills et al., 2012).
Originally named sjögrenite. Subsequently recognised as a polytype of pyroaurite and accordingly discredited as a species (Mills et al., 2012).
Unique Identifiers
Mindat ID:
3678
Long-form identifier:
mindat:1:1:3678:4
Classification of Pyroaurite-2H
5.DA.45
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
16b.6.1.3
16b : HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
6 : AmBn(XO3)pZqxH2O & with (m+n):p = 8:1
16b : HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
6 : AmBn(XO3)pZq
11.13.3
11 : Carbonates
13 : Carbonates of Fe
11 : Carbonates
13 : Carbonates of Fe
Physical Properties of Pyroaurite-2H
Vitreous, Waxy, Pearly
Transparency:
Transparent
Colour:
White, yellowish green, brownish green, yellowish white, brownish white
Hardness:
2½ on Mohs scale
Cleavage:
Perfect
{0001}
{0001}
Density:
2.08 - 2.14 g/cm3 (Measured) 2.11 g/cm3 (Calculated)
Optical Data of Pyroaurite-2H
Type:
Uniaxial (-)
RI values:
nω = 1.573 nε = 1.55
Max. Birefringence:
δ = 0.023
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Low (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Chemistry of Pyroaurite-2H
Mindat Formula:
Mg6Fe3+2(OH)16(CO3) · 4H2O
Element Weights:
Crystallography of Pyroaurite-2H
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P63/mmc
Cell Parameters:
a = 3.113(3) Å, c = 15.61(1) Å
Ratio:
a:c = 1 : 5.014
Unit Cell V:
131.01 ų (Calculated from Unit Cell)
Morphology:
Thin plates {0001}, with a hexagonal outline and striated and indistinct lateral faces.
Comment:
Z = 1/4
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.78 Å | (10) |
| 3.90 Å | (6) |
| 2.65 Å | (4) |
| 2.54 Å | (5) |
| 2.39 Å | (3) |
| 2.21 Å | (5) |
| 1.87 Å | (5) |
First Recorded Occurrence of Pyroaurite-2H
Synonyms of Pyroaurite-2H
Other Language Names for Pyroaurite-2H
Common Associates
Associations Based on Photo Data:
| 6 photos of Pyroaurite-2H associated with Hydromagnesite | Mg5(CO3)4(OH)2 · 4H2O |
| 6 photos of Pyroaurite-2H associated with Magnesite | MgCO3 |
| 5 photos of Pyroaurite-2H associated with Tetraferriphlogopite | KMg3(Si3Fe3+)O10(OH)2 |
| 5 photos of Pyroaurite-2H associated with Pyroaurite | Mg6Fe3+2(OH)16[CO3] · 4H2O |
| 5 photos of Pyroaurite-2H associated with Pokrovskite | Mg2(CO3)(OH)2 |
| 3 photos of Pyroaurite-2H associated with Calcite | CaCO3 |
| 2 photos of Pyroaurite-2H associated with Kassite | CaTi2O4(OH)2 |
| 2 photos of Pyroaurite-2H associated with Magnetite | Fe2+Fe3+2O4 |
| 2 photos of Pyroaurite-2H associated with Heazlewoodite | Ni3S2 |
| 2 photos of Pyroaurite-2H associated with Desautelsite | Mg6Mn3+2(OH)16[CO3] · 4H2O |
Related Minerals - Strunz-mindat Grouping
| 5.DA. | Alexkhomyakovite | K6(Ca2Na)(CO3)5Cl · 6H2O |
| 5.DA. | Amoraite | Ca12Al6(OH)36(CO3)2(SO3) · 15H2O |
| 5.DA. | Lincioite | [Ni2+2Fe3+4O2(OH)10](CO3) · 3H2O |
| 5.DA.05 | Dypingite | Mg5(CO3)4(OH)2 · 5H2O |
| 5.DA.05 | 'UM1986-10-CO:ClHMgMnZn (also called Mineral F, Dunn, 1995)' | Mg5(Zn,Mn)3(CO3)2(OH,Cl)12 · H2O |
| 5.DA.05 | 'UM1987-01-CO:HMgS' | Mg4(CO3)2(OH)4 · 6H2O ? |
| 5.DA.05 | Giorgiosite | Mg5(CO3)4(OH)2 · 5-6H2O |
| 5.DA.05 | Hydromagnesite | Mg5(CO3)4(OH)2 · 4H2O |
| 5.DA.05 | Widgiemoolthalite | Ni5(CO3)4(OH)2 · 5H2O |
| 5.DA.10 | Artinite | Mg2(CO3)(OH)2 · 3H2O |
| 5.DA.10 | Chlorartinite | Mg2(CO3)(OH)Cl · 2H2O |
| 5.DA.10 | Indigirite | Mg2Al2(CO3)4(OH)2 · 15H2O |
| 5.DA.15 | Zaratite | Ni3(CO3)(OH)4 · 4H2O ? |
| 5.DA.15 | Otwayite | Ni2(CO3)(OH)2 · H2O |
| 5.DA.20 | Kambaldaite | NaNi4(CO3)3(OH)3 · 3H2O |
| 5.DA.25 | Callaghanite | Cu2Mg2(CO3)(OH)6 · 2H2O |
| 5.DA.30 | Claraite | (Cu,Zn)15(CO3)4(AsO4)2(SO4)(OH)14 · 7H2O |
| 5.DA.35 | Hydroscarbroite | Al14(CO3)3(OH)36 · nH2O |
| 5.DA.35 | Scarbroite | Al5(CO3)(OH)13 · 5H2O |
| 5.DA.40 | Karchevskyite | Mg18Al9(OH)54Sr2(CO3)9(H2O)6(H3O)5 |
| 5.DA.40 | 'UM1987-05-OH:AlCMg' | Mg4Al2(OH)12(CO3,SO4) · 3H2O |
| 5.DA.40 | Quintinite | Mg4Al2(OH)12(CO3) · 3H2O |
| 5.DA.40 | Charmarite | Mn2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.40 | Caresite | Fe2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Hydrotalcite-2H' | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | 'Stichtite-2H' | Mg6(Cr,Al)2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | Brugnatellite | Mg6Fe3+(CO3)(OH)13 · 4H2O |
| 5.DA.45 | Zaccagnaite | Zn4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | Liudongshengite | Zn4Cr2(OH)12(CO3) · 3H2O |
| 5.DA.45 | Chlormagaluminite | Mg4Al2(OH)12Cl2 · 3H2O |
| 5.DA.50 | Pyroaurite | Mg6Fe3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Takovite | Ni6Al2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Reevesite | Ni6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.50 | Kaznakhtite | Ni6Co3+2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Comblainite | Ni4Co2(OH)12[CO3] · 3H2O |
| 5.DA.50 | Marioantofilliite | [Cu4Al2(OH)12](CO3) · 3H2O |
| 5.DA.50 | Hydrotalcite | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Stichtite | Mg6Cr3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Desautelsite | Mg6Mn3+2(OH)16[CO3] · 4H2O |
| 5.DA.55 | Coalingite | Mg10Fe3+2(OH)24[CO3] · 2H2O |
| 5.DA.55 | Akopovaite | Al4Li2(OH)12(CO3)(H2O)3 |
| 5.DA.60 | Šlikite | Zn2Mg(CO3)2(OH)2 · 4H2O |
| 5.DA.65 | Marklite | Cu5(CO3)2(OH)6 · 6H2O |
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 Pyroaurite-2H
mindat.org URL:
https://www.mindat.org/min-3678.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
Mineral Dealers:
References for Pyroaurite-2H
Reference List:
Frondel, Clifford (1941) Constitution and polymorphism of the pyroaurite and sjögrenite groups. American Mineralogist, 26 (5) 295-315
Localities for Pyroaurite-2H
Showing 32 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.
Australia | |
| Bottrill et al. (2008) |
| Bottrill & Taheri +1 other reference |
| Bottrill et al. (2008) |
| Bottrill et al. (2008) |
Austria | |
| Löffler et al. (2011) |
Canada | |
| Sabina (1967) |
Germany | |
| Blaß et al. (1994) +1 other reference |
| Schnorrer-Köhler (1991) |
Italy | |
| Conti et al. (1970) |
| Bortolozzi et al. (2013) |
| Boscardin et al. (2011) |
| Antonio Zordan collection |
| Boscardin et al. (2011) |
| Boscardin et al. (2011) |
Japan | |
| |
| Petrov (n.d.) | |
| ITO et al. (1979) +1 other reference | |
Kazakhstan | |
| Pekov (1998) |
Lebanon | |
| Kruszewski (2019) |
Poland | |
| Ł. Kruszewski (PXRD data) |
Russia | |
| Mazurov et al. (2007) |
| maurice.strahlen.org (2003) +1 other reference |
Sweden (FRL) | |
| Aminoff (1931) +2 other references |
| Gatedal (n.d.) | |
| Sandström et al. (2009) |
| Linden (2002) | |
| Östra Värmlands Mineral Society | |
UK | |
| Dr Stephen Moreton collection. |
USA | |
| Murdoch (1966) +2 other references |
| Pemberton (1983) +1 other reference |
| www.minresco.com/syst/s.htm | |
| Leavens et al. (1981) +2 other references |
Grama Valley Quarry, Laghi, Vicenza Province, Veneto, Italy