Picromerite
A valid IMA mineral species - grandfathered
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About Picromerite
Formula:
K2Mg(SO4)2 · 6H2O
Colour:
Colourless, white, reddish, yellowish, grayish; colourless in transmitted light.
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
2.028
Crystal System:
Monoclinic
Member of:
Name:
From the Greek for "bitter" and "part" in allusion to the presence of magnesium and was originally applied to material crystallized from an aqueous solution of mixed salts from Vesuvius fumaroles.
Picromerite Group.
Fresh picromerite is colorless. Specimens may dehydrate in collections within days to years (according to the conditions) to white, opaque leonite.
Picromerite-type compounds are labeled Tutton salts in chemistry.
Fresh picromerite is colorless. Specimens may dehydrate in collections within days to years (according to the conditions) to white, opaque leonite.
Picromerite-type compounds are labeled Tutton salts in chemistry.
Unique Identifiers
Mindat ID:
3206
Long-form identifier:
mindat:1:1:3206:9
GUID
(UUID V4):
(UUID V4):
6cbe7f45-a421-45ee-863f-38f440f2bb8f
IMA Classification of Picromerite
Approved, 'Grandfathered' (first described prior to 1959)
First published:
1855
Classification of Picromerite
7.CC.60
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
29.3.6.1
29 : HYDRATED ACID AND NORMAL SULFATES
3 : A2B(XO4)2·xH2O
29 : HYDRATED ACID AND NORMAL SULFATES
3 : A2B(XO4)2·xH2O
25.3.15
25 : Sulphates
3 : Sulphates of Mg
25 : Sulphates
3 : Sulphates of Mg
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 |
|---|---|---|
| Pmr | 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 Picromerite
Vitreous
Transparency:
Transparent
Colour:
Colourless, white, reddish, yellowish, grayish; colourless in transmitted light.
Comment:
Tints due to admixed materials
Streak:
White
Hardness:
2½ on Mohs scale
Cleavage:
Perfect
On {201}, perfect.
On {201}, perfect.
Density:
2.028 g/cm3 (Measured) 2.031 g/cm3 (Calculated)
Comment:
Measured on artificial material.
Optical Data of Picromerite
Type:
Biaxial (+)
RI values:
nα = 1.461 nβ = 1.463 nγ = 1.476
2V:
Measured: 48° , Calculated: 46°
Max Birefringence:
δ = 0.015
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
r > v strong
Chemistry of Picromerite
Mindat Formula:
K2Mg(SO4)2 · 6H2O
Crystallography of Picromerite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P2/b
Setting:
P2/a
Cell Parameters:
a = 9.066 Å, b = 12.254 Å, c = 6.128 Å
β = 104.78°
β = 104.78°
Ratio:
a:b:c = 0.74 : 1 : 0.5
Unit Cell V:
658.26 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Short prismatic [001]. Crusts on other salts; also massive.
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0004776 | Picromerite | Bosi F, Belardi G, Ballirano P (2009) Structural features in Tutton's salts K2[M2+(H2O)6](SO4)2, with M2+= Mg, Fe, Co, Ni, Cu, and Zn American Mineralogist 94 74-82 |  | 2009 | synthetic | 0 | 293 |
| 0010626 | Picromerite | Kannan K K, Viswamitra M A (1965) Crystal structure of magnesium potassium sulfate hexahydrate MgK2(SO4)2*6(H2O) Zeitschrift fur Kristallographie 122 161-174 | | 1965 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.16 Å | (85) |
| 4.06 Å | (95) |
| 3.71 Å | (100) |
| 3.16 Å | (40) |
| 3.06 Å | (70) |
| 2.964 Å | (60) |
| 2.813 Å | (40) |
Comments:
Powder data from synthetic material.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 25 : Evaporites (prebiotic) | |
| Stage 7: Great Oxidation Event | <2.4 |
| 45a : [Sulfates, arsenates, selenates, antimonates] | |
| 45b : [Other oxidized fumarolic minerals] | |
| 47a : [Near-surface hydration of prior minerals] | |
| 47b : [Sulfates and sulfites] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals | |
| 56 : Slag and smelter minerals (see also #51 and #55) |
Geological Setting:
In kainite zones of some oceanic salt deposits.
Type Occurrence of Picromerite
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
Active volcanic fumaroles.
Reference:
Guarini, G., Palmieri, L., Scacchi, A. (1855) Chapter 5. Esame mineralogico-chimico delle produzioni dell'incendio. in Memoria sullo Incendio Vesuviano, Gaetano Nobile (Napoli): 165-200 (191).
Synonyms of Picromerite
Other Language Names for Picromerite
Italian:Picromeride
Russian:Пикромерит
Simplified Chinese:软钾镁矾
Spanish:Picromerita
Traditional Chinese:軟鉀鎂礬
Relationship of Picromerite to other Species
Member of:
Other Members of this group:
| Boussingaultite | (NH4)2Mg(SO4)2 · 6H2O | Mon. 2/m : P21/b |
| Cyanochroite | K2Cu(SO4)2 · 6H2O | Mon. 2/m : P21/b |
| Katerinopoulosite | (NH4)2Zn(SO4)2 · 6H2O | Mon. 2/m : P21/b |
| Mohrite | (NH4)2Fe(SO4)2 · 6H2O | Mon. 2/m : P21/b |
| Nickelboussingaultite | (NH4)2Ni(SO4)2 · 6H2O | Mon. 2/m : P21/b |
| Nickelpicromerite | K2Ni(SO4)2 · 6H2O | Mon. 2/m : P21/b |
Common Associates
Associated Minerals Based on Photo Data:
| 18 photos of Picromerite associated with Halite | NaCl |
| 3 photos of Picromerite associated with Leonite | K2Mg(SO4)2 · 4H2O |
| 1 photo of Picromerite associated with Konyaite | Na2Mg(SO4)2 · 5H2O |
| 1 photo of Picromerite associated with Blödite | Na2Mg(SO4)2 · 4H2O |
| 1 photo of Picromerite associated with Hexahydrite | MgSO4 · 6H2O |
Related Minerals - Strunz-mindat Grouping
| 7.CC. | Cobaltoblödite | Na2Co(SO4)2 · 4H2O |
| 7.CC. | Andychristyite | PbCu2+Te6+O5(H2O) |
| 7.CC. | Ammoniovoltaite | (NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18 |
| 7.CC.05 | Krausite | KFe(SO4)2 · H2O |
| 7.CC.10 | Tamarugite | NaAl(SO4)2 · 6H2O |
| 7.CC.15 | Kalinite | KAl(SO4)2 · 11H2O |
| 7.CC.15 | Mendozite | NaAl(SO4)2 · 11H2O |
| 7.CC.20 | Lonecreekite | (NH4)Fe3+(SO4)2 · 12H2O |
| 7.CC.20 | Alum-(K) | KAl(SO4)2 · 12H2O |
| 7.CC.20 | Alum-(Na) | NaAl(SO4)2 · 12H2O |
| 7.CC.20 | Tschermigite | (NH4)Al(SO4)2 · 12H2O |
| 7.CC.20 | Lanmuchangite | Tl+Al(SO4)2 · 12H2O |
| 7.CC.25 | Voltaite | K2Fe2+5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Zincovoltaite | K2Zn5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Pertlikite | K2(Fe2+,Mg)2Mg4Fe3+2Al(SO4)12 · 18H2O |
| 7.CC.25 | Ammoniomagnesiovoltaite | (NH4)2Mg2+5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Magnesiovoltaite | K2Mg5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.30 | Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| 7.CC.35 | Ferrinatrite | Na3Fe(SO4)3 · 3H2O |
| 7.CC.40 | Goldichite | KFe(SO4)2 · 4H2O |
| 7.CC.45 | Löweite | Na12Mg7(SO4)13 · 15H2O |
| 7.CC.50 | Blödite | Na2Mg(SO4)2 · 4H2O |
| 7.CC.50 | Nickelblödite | Na2(Ni,Mg)(SO4)2 · 4H2O |
| 7.CC.50 | Changoite | Na2Zn(SO4)2 · 4H2O |
| 7.CC.55 | Leonite | K2Mg(SO4)2 · 4H2O |
| 7.CC.55 | Mereiterite | K2Fe(SO4)2 · 4H2O |
| 7.CC.60 | Boussingaultite | (NH4)2Mg(SO4)2 · 6H2O |
| 7.CC.60 | Cyanochroite | K2Cu(SO4)2 · 6H2O |
| 7.CC.60 | Mohrite | (NH4)2Fe(SO4)2 · 6H2O |
| 7.CC.60 | Nickelboussingaultite | (NH4)2Ni(SO4)2 · 6H2O |
| 7.CC.60 | Nickelpicromerite | K2Ni(SO4)2 · 6H2O |
| 7.CC.60 | Katerinopoulosite | (NH4)2Zn(SO4)2 · 6H2O |
| 7.CC.65 | Polyhalite | K2Ca2Mg(SO4)4 · 2H2O |
| 7.CC.70 | Leightonite | K2Ca2Cu(SO4)4 · 2H2O |
| 7.CC.75 | Amarillite | NaFe(SO4)2 · 6H2O |
| 7.CC.80 | Konyaite | Na2Mg(SO4)2 · 5H2O |
| 7.CC.85 | Wattevilleite | Na2Ca(SO4)2 · 4H2O (?) |
| 7.CC.85 | Xocolatlite | Ca2Mn4+2(Te6+O6)2 · H2O |
| 7.CC.90 | Eckhardite | (Ca,Pb)Cu2+Te6+O5(H2O) |
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 Picromerite
mindat.org URL:
https://www.mindat.org/min-3206.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Picromerite
Localities for Picromerite
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 | |
| Harris et al. (2003) |
Austria | |
| Exel (1993) |
| Exel (1993) |
| Exel (1993) |
Cape Verde | |
| Silva et al. (2019) |
Chile | |
| Palache et al. (1951) |
China | |
| Sun Da-peng et al. (2002) |
| Shaoxiu Yang (1991) |
| Dongsheng Hu (1990) +1 other reference |
| Shaoxiu Yang (1991) +1 other reference |
| Xiying Zhang et al. (2007) |
| Mianping Zheng and Xifang Liu (2010) |
| Lichun Ma et al. (2010) |
| Yanling Tang (2005) | |
| Bingxiao Li (1992) |
| Huaning Qiu et al. (2000) |
Czech Republic | |
| Jan Hloušek |
| Dalibor Matýsek |
| Dokoupilova P. |
| Hršelová et al. (2013) | |
Germany | |
| A.Dietrich (2004) |
| Weiß (1990) |
| Weiß (1990) |
| Weiß (1990) |
| |
| Andreas Gerstenberg collection |
| Bode "Mineralien und Fundstellen BRD" ... |
| www.mineralienatlas.de (n.d.) |
| www.mineralienatlas.de (n.d.) |
| |
| Naumann |
| ... | |
| Palache et al. (1951) |
| T. Witzke & F. Rüger: Lapis 1998 (7/8) |
| www.minrec.org (n.d.) |
Iran | |
| Mr. Maziar Nazari |
Italy (TL) | |
| Russo |
| Pelloux (1927) +1 other reference | |
| Piccoli et al. (2007) |
| Neschen (n.d.) |
| www.cse.speleo.it |
Kazakhstan | |
| Pekov et al. (1993) |
Peru | |
| Ciesielczuk et al. (2013) |
Poland | |
| Wachowiak et al. (2016) |
| Kruszewski (2013) |
| Łukasz Kruszewski (2012) |
UK | |
| Smith et al. (2014) |
| Kemp et al. (2016) | |
Ukraine | |
| Palache et al. (1951) |
| Palache et al. (1951) |
| ... |
USA | |
| Hon |
| Northrop et al. (1996) |
| Hawley +5 other references |
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Neuhof-Ellers Potash Works, Neuhof, Fulda, Kassel Region, Hesse, Germany