Ikaite
A valid IMA mineral species
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About Ikaite
Formula:
CaCO3 · 6H2O
Colour:
Brown
Specific Gravity:
1.77
Crystal System:
Monoclinic
Name:
For the type locality Ikka Fjord, Greenland (formerly spelled Ika).
Type Locality:
Readily dehydrates to calcite above 8°C.
The resulting pseudomorph of calcite after ikaite is also called "glendonite."
Compare Unnamed (Amorphous Calcium Carbonate).
The resulting pseudomorph of calcite after ikaite is also called "glendonite."
Compare Unnamed (Amorphous Calcium Carbonate).
Unique Identifiers
Mindat ID:
2007
Long-form identifier:
mindat:1:1:2007:3
Similar Names
IMA Classification of Ikaite
Approved
IMA Formula:
Ca(CO3) · 6H2O
First published:
1963
Type description reference:
Classification of Ikaite
5.CB.25
5 : CARBONATES (NITRATES)
C : Carbonates without additional anions, with H2O
B : With large cations (alkali and alkali-earth carbonates)
5 : CARBONATES (NITRATES)
C : Carbonates without additional anions, with H2O
B : With large cations (alkali and alkali-earth carbonates)
15.1.4.1
15 : HYDRATED NORMAL CARBONATES
1 : A(XO3)·xH2O
15 : HYDRATED NORMAL CARBONATES
1 : A(XO3)·xH2O
11.4.5
11 : Carbonates
4 : Carbonates of Ca
11 : Carbonates
4 : Carbonates of Ca
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 |
|---|---|---|
| Ika | 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 Ikaite
Transparency:
Translucent
Colour:
Brown
Tenacity:
Fragile
Density:
1.77 g/cm3 (Measured) 1.833 g/cm3 (Calculated)
Optical Data of Ikaite
Type:
Biaxial (-)
RI values:
nα = 1.455 - 1.460 nβ = 1.535 - 1.538 nγ = 1.545
2V:
Measured: 38° to 45°, Calculated: 30°
Max. Birefringence:
δ = 0.085 - 0.090
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.
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.
Surface Relief:
Moderate
Dispersion:
distinct
Optical Extinction:
Y = b; Z ∧ c = 17°.
Chemistry of Ikaite
Mindat Formula:
CaCO3 · 6H2O
Element Weights:
Elements listed:
Crystallography of Ikaite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 8.87 Å, b = 8.23 Å, c = 11.02 Å
β = 110.2°
β = 110.2°
Ratio:
a:b:c = 1.078 : 1 : 1.339
Unit Cell V:
754.98 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Crystals tabular {001} or pseudomorphous after a rhombohedral carbonate mineral.
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) |
|---|---|---|---|---|---|---|---|
| 0010853 | Ikaite | Hesse K F, Kuppers H, Suess E (1983) Refinement of the structure of ikaite, CaCO3*6(H2O) Zeitschrift fur Kristallographie 163 227-231 |  | 1983 | Bransfield Strait, Antarctica | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.171 Å | (100) |
| 2.643 Å | (85) |
| 2.629 Å | (70) |
| 2.804 Å | (50) |
| 2.464 Å | (33) |
| 4.162 Å | (29) |
| 2.774 Å | (27) |
Comments:
Synthetic, ICDD 37-416.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 18 : Minerals formed by freezing |
Geological Setting:
Forms in sea water and lake water in anaerobic, organic-rich periglacial and glaciomarine environments near 0°C, readily converting to calcite at higher temperatures.
Type Occurrence of Ikaite
Place of Conservation of Type Material:
n.d.
Geological Setting of Type Material:
Forms in cold water near freezing point.
Synonyms of Ikaite
Other Language Names for Ikaite
Common Associates
Associated Minerals Based on Photo Data:
| 23 photos of Ikaite associated with Calcite | CaCO3 |
| 19 photos of Ikaite associated with Glendonite | CaCO3 |
| 10 photos of Ikaite associated with Black shale | |
| 10 photos of Ikaite associated with Opal | SiO2 · nH2O |
| 7 photos of Ikaite associated with Organic-rich-sediment | |
| 5 photos of Ikaite associated with Dolomite | CaMg(CO3)2 |
| 5 photos of Ikaite associated with Goethite | Fe3+O(OH) |
| 5 photos of Ikaite associated with Sphalerite | ZnS |
| 4 photos of Ikaite associated with Pyrite | FeS2 |
| 4 photos of Ikaite associated with Hematite | Fe2O3 |
Related Minerals - Strunz-mindat Grouping
| 5.CB. | Paulišite | Ca2Zn(CO3)3 · 2H2O |
| 5.CB.05 | Thermonatrite | Na2CO3 · H2O |
| 5.CB.10 | Natron | Na2CO3 · 10H2O |
| 5.CB.15 | Trona | Na3H(CO3)2 · 2H2O |
| 5.CB.20 | Monohydrocalcite | CaCO3 · H2O |
| 5.CB.30 | Pirssonite | Na2Ca(CO3)2 · 2H2O |
| 5.CB.35 | Gaylussite | Na2Ca(CO3)2 · 5H2O |
| 5.CB.40 | Chalconatronite | Na2Cu(CO3)2 · 3H2O |
| 5.CB.45 | Baylissite | K2Mg(CO3)2 · 4H2O |
| 5.CB.50 | Tuliokite | Na6BaTh(CO3)6 · 6H2O |
Other Information
Special Storage/
Display Requirements:
Display Requirements:
Readily dehydrates to calcite above 8 °C.
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 Ikaite
mindat.org URL:
https://www.mindat.org/min-2007.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
References for Ikaite
Reference List:
Bischoff, James L., Fitzpatrick, John A., Rosenbauer, Robert J. (1993) The Solubility and Stabilization of Ikaite (CaCO3·6H2O) from 0° to 25°C: Environmental and Paleoclimatic Implications for Thinolite Tufa. The Journal of Geology, 101 (1) 21-33 doi:10.1086/648194
Bischoff, James L., Stine, Scott, Rosenbauer, Robert J., Fitzpatrick, John A., Stafford, Thomas W. (1993) Ikaite precipitation by mixing of shoreline springs and lake water, Mono Lake, California, USA. Geochimica et Cosmochimica Acta, 57 (16) 3855-3865 doi:10.1016/0016-7037(93)90339-x
Swainson, Ian P., Hammond, Robert P. (2001) Ikaite, CaCO3·6H2O: Cold comfort for glendonites as paleothermometers. American Mineralogist, 86 (11) 1530-1533 doi:10.2138/am-2001-11-1223
Tlili, M. M., Amor, M. Ben, Gabrielli, C., Joiret, S., Maurin, G., Rousseau, P. (2002) Characterization of CaCO3 hydrates by micro-Raman spectroscopy. Journal of Raman Spectroscopy, 33 (1). 10-16 doi:10.1002/jrs.806
Shahar, A. (2005) The stability and Raman spectra of ikaite, CaCO3·6H2O, at high pressure and temperature. American Mineralogist, 90 (11) 1835-1839 doi:10.2138/am.2005.1783
Localities for Ikaite
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.
Antarctica | |
| Dieckmann et al. (2008) |
| Swainson et al. (2001) |
| Whiticar et al. (2022) | |
| Dieckmann et al. (2008) | |
Arctic Ocean | |
| Schultz et al. (2023) | |
Australia | |
| Keith F Compton collection |
Canada | |
| Last et al. (2013) |
Czech Republic | |
| Žák K. et al. (2010) |
Estonia | |
| Soesoo et al. (2023) |
| Soesoo et al. (2023) |
Greenland | |
| Stockmann et al. (2022) |
| Pauly (1963) +3 other references | |
Japan | |
| Genko. 91 (6) |
Norway | |
| Palache et al. (1951) | |
Pacific Ocean | |
| Schultz et al. (2023) | |
| Greinert et al. (2004) |
Romania | |
| Bogdan P. Onac (2017) |
| Slavoaca |
Russia | |
| Actually 'glendonite' |
South Georgia and the South Sandwich Islands | |
| Schultz et al. (2023) | |
UK | |
| Field et al. (2017) |
USA | |
| Schultz et al. (2023) |
| Kennedy et al. (1987, October) | |
| Geology 21:971-974. +1 other reference |
Olenitsa River, White Sea Coast, Murmansk Oblast, Russia