Görgeyite
A valid IMA mineral species - grandfathered
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About Görgeyite
Rudolf Görgey
Formula:
K2Ca5(SO4)6 · H2O
Colour:
Colorless, white, pale yellow, greenish yellow
Lustre:
Vitreous
Hardness:
3½
Specific Gravity:
2.90 - 2.93
Crystal System:
Monoclinic
Name:
Named in honor of Rudolf Görgey von Görgö und Toporcz (Rolf Görgey) (23 June 1886, Budapest, Hungary - 25 May 1915, Rudnik, Poland), mineralogist at the University of Vienna. He first studied zeolites and later salt/potash deposits. Through his work, he visited many European countries and built a mineral collection.
Isostructural with:
This page provides mineralogical data about Görgeyite.
Name Encoding
ASCII-7:
Gorgeyite
Unique Identifiers
Mindat ID:
1748
Long-form identifier:
mindat:1:1:1748:6
IMA Classification of Görgeyite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
K2Ca5(S6+O4)6·H2O
First published:
1953
Classification of Görgeyite
7.CD.30
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
D : With only large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
D : With only large cations
Dana 7th ed.:
29.4.7.1
29.4.7.1
29 : HYDRATED ACID AND NORMAL SULFATES
4 : AmBn(XO4)p·xH2O, with (m+n):p < 3:2 and > 1:1
29 : HYDRATED ACID AND NORMAL SULFATES
4 : AmBn(XO4)p·xH2O, with (m+n):p < 3:2 and > 1:1
25.4.9
25 : Sulphates
4 : Sulphates of Ca, Sr and Ba
25 : Sulphates
4 : Sulphates of Ca, Sr and Ba
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 |
|---|---|---|
| Gög | 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 Görgeyite
Vitreous
Transparency:
Translucent
Colour:
Colorless, white, pale yellow, greenish yellow
Streak:
(not reported)
Hardness:
3½ on Mohs scale
Cleavage:
Imperfect/Fair
Distinct on {100}
Distinct on {100}
Fracture:
Splintery, Hackly
Density:
2.90 - 2.93 g/cm3 (Measured) 2.90 g/cm3 (Calculated)
Optical Data of Görgeyite
Type:
Biaxial (+)
RI values:
nα = 1.560 nβ = 1.569 nγ = 1.584
2V:
Measured: 79° to 80°, Calculated: 78°
Max. Birefringence:
δ = 0.024
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:
Moderate (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 biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
none
Chemistry of Görgeyite
Mindat Formula:
K2Ca5(SO4)6 · H2O
Element Weights:
Crystallography of Görgeyite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 17.51 Å, b = 6.83 Å, c = 18.23 Å
β = 113.3°
β = 113.3°
Ratio:
a:b:c = 2.564 : 1 : 2.669
Unit Cell V:
2,002.38 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Tabular on {001}. Showing {001}, {100}, {111}, {110}.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.005 Å | (100) |
| 3.164 Å | (70) |
| 2.817 Å | (40) |
| 2.756 Å | (30) |
| 1.841 Å | (25) |
| 1.896 Å | (20) |
| 3.029 Å | (15) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 25 : Evaporites (prebiotic) | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 50 : Coal and/or oil shale minerals | <0.36 |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) |
Type Occurrence of Görgeyite
Place of Conservation of Type Material:
Natural History Museum, Vienna, Austria, M474.
Harvard University, Cambridge, Massachusetts, USA, 107559.
Harvard University, Cambridge, Massachusetts, USA, 107559.
Geological Setting of Type Material:
Evaporite deposit
Synonyms of Görgeyite
Other Language Names for Görgeyite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 7.CD. | Argesite | (NH4)7Bi3Cl16 |
| 7.CD. | Campostriniite | (Bi3+,Na)3(NH4,K)2Na2(SO4)6 · H2O |
| 7.CD.05 | Matteuccite | NaHSO4 · H2O |
| 7.CD.10 | Mirabilite | Na2SO4 · 10H2O |
| 7.CD.15 | Lecontite | (NH4)Na(SO4) · 2H2O |
| 7.CD.20 | Hydroglauberite | Na10Ca3(SO4)8 · 6H2O |
| 7.CD.25 | Eugsterite | Na4Ca(SO4)3 · 2H2O |
| 7.CD.35 | Syngenite | K2Ca(SO4)2 · H2O |
| 7.CD.35 | Antofagastaite | Na2Ca(SO4)2 · 1.5H2O |
| 7.CD.35 | Koktaite | (NH4)2Ca(SO4)2 · H2O |
| 7.CD.40 | Gypsum | CaSO4 · 2H2O |
| 7.CD.45 | Chinleite-(Y) | NaY(SO4)2 · H2O |
| 7.CD.45 | Bassanite | Ca(SO4) · 0.5H2O |
| 7.CD.45 | Chinleite-(Nd) | NaNd(SO4)2 · H2O |
| 7.CD.45 | Chinleite-(Ce) | NaCe(SO4)2(H2O) |
| 7.CD.50 | Zircosulfate | (Zr,Ti)(SO4)2 · 4H2O |
| 7.CD.55 | Schieffelinite | Pb10Te6+6O20(OH)14(SO4)(H2O)5 |
| 7.CD.60 | Montanite | Bi2(TeO6) · nH2O |
| 7.CD.65 | Omongwaite | Na2Ca5(SO4)6 · 3H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 8.9575% | 2,777 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
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 Görgeyite
mindat.org URL:
https://www.mindat.org/min-1748.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
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References for Görgeyite
Localities for Görgeyite
Showing 16 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 | |
| Snow et al. (2014) |
Austria (TL) | |
| Mayrhofer (1953) |
Canada | |
| Shang (2000) |
China | |
| Anthony |
| Keqin Cai et al. (1985) +1 other reference |
Germany | |
| Witzke et al. (2015) |
Greece | |
| Smith et al. (1964) |
Iran | |
| Ghadimi et al. (2013) |
Israel | |
| Anenburg et al. (2013) |
Italy | |
| Pellino et al. (2025) |
| Cavarretta et al. (1981) +3 other references |
| Cavarretta et al. (1982) +2 other references | |
Kazakhstan | |
| Pavel M. Kartashov (n.d.) +2 other references |
Poland | |
| Cu +2 other references |
Russia | |
| Chaykovsky et al. (2011) |
| kimberlites of Udachnaya-East pipe (Siberia) +1 other reference |
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Inder B deposit and salt dome, Inder District, Atyrau Region, Kazakhstan