Portlandite
A valid IMA mineral species - grandfathered
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About Portlandite
Formula:
Ca(OH)2
Colour:
Colorless, white to greenish white
Lustre:
Pearly
Hardness:
2 - 3
Specific Gravity:
2.227 - 2.233
Crystal System:
Trigonal
Member of:
Name:
In allusion to the occurrence of Ca(OH)2 as a product of hydration of portland cement.
Type Locality:
Rare in nature, but an important phase in cement materials and concrete. Indicative of a very high pH value.
Unique Identifiers
Mindat ID:
3264
Long-form identifier:
mindat:1:1:3264:9
IMA Classification of Portlandite
Approved, 'Grandfathered' (first described prior to 1959)
First published:
1933
Classification of Portlandite
4.FE.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
E : Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
E : Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
6.2.1.4
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
7.4.12
7 : Oxides and Hydroxides
4 : Oxides of Be, Mg and the alkaline earths
7 : Oxides and Hydroxides
4 : Oxides of Be, Mg and the alkaline earths
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 |
|---|---|---|
| Por | 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 Portlandite
Pearly
Transparency:
Transparent
Comment:
Pearly on cleavages.
Colour:
Colorless, white to greenish white
Streak:
White
Hardness:
2 - 3 on Mohs scale
Tenacity:
Sectile
Cleavage:
Perfect
{0001}
{0001}
Density:
2.227 - 2.233 g/cm3 (Measured) 2.26 g/cm3 (Calculated)
Optical Data of Portlandite
Type:
Uniaxial (-)
RI values:
nω = 1.575 nε = 1.547
Max. Birefringence:
δ = 0.028
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 Portlandite
Mindat Formula:
Ca(OH)2
Elements listed:
Crystallography of Portlandite
Crystal System:
Trigonal
Class (H-M):
3m(32/m) - Hexagonal Scalenohedral
Space Group:
P3m1
Setting:
P3m1
Cell Parameters:
a = 3.589(8) Å, c = 4.911(14) Å
Ratio:
a:c = 1 : 1.368
Unit Cell V:
54.78 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Minute hexagonal plates. Tabular {0001}, with {1010} as linear faces (artificial material). fibrous, powdery, massive.
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0020244 | Portlandite | Iizuka R, Yagi T, Komatsu K, Gotou H, Tsuchiya T, Kusaba K, Kagi H (2013) Crystal structure of the high-pressure phase of calcium hydroxide, portlandite: In situ powder and single crystal X-ray diffraction study American Mineralogist 98 1421-1428 | 2013 | synthetic | 8.9 | 293 | |
| 0000117 | Portlandite | Henderson D M, Gutowsky H S (1962) A nuclear magnetic resonance determination of the hydrogen positions in Ca(OH)2 American Mineralogist 47 1231-1251 |  | 1962 | 0 | 298 | |
| 0009877 | Portlandite | Desgranges L, Grebille D, Calvarin g, Chevrier G, Floquet N, Niepce J (1993) Hydrogen thermal motion in calcium hydroxide: Ca (O H)2 _cod_database_code 1001788 Acta Crystallographica B49 812-817 |  | 1993 | 0 | 293 | |
| 0009876 | Portlandite | Desgranges L, Grebille D, Calvarin g, Chevrier G, Floquet N, Niepce J (1993) Hydrogen thermal motion in calcium hydroxide: Ca (O H)2 _cod_database_code 1001787 Acta Crystallographica B49 812-817 | | 1993 | 0 | 293 | |
| 0009875 | Portlandite | Desgranges L, Grebille D, Calvarin g, Chevrier G, Floquet N, Niepce J (1993) Hydrogen thermal motion in calcium hydroxide: Ca (O H)2 _cod_database_code 1001769 Acta Crystallographica B49 812-817 | | 1993 | 0 | 293 | |
| 0009874 | Portlandite | Desgranges L, Grebille D, Calvarin g, Chevrier G, Floquet N, Niepce J (1993) Hydrogen thermal motion in calcium hydroxide: Ca (O H)2 _cod_database_code 1001768 Acta Crystallographica B49 812-817 | | 1993 | 0 | 293 | |
| 0011777 | Portlandite | Wyckoff R W G (1963) Second edition. Interscience Publishers, New York, New York Crystal Structures 1 239-444 | 1963 | 0 | 293 | ||
| 0016656 | Portlandite | Busing W, Levy H (1957) Neutron diffraction study of calcium hydroxide _cod_database_code 1008781 Journal of Chemical Physics 26 563-568 | 1957 | 0 | 293 | ||
| 0012953 | Portlandite | Busing W, Levy H (1957) Neutron diffraction study of calcium hydroxide _cod_database_code 1000045 Journal of Chemical Physics 26 563-568 | 1957 | 0 | 293 | ||
| 0000116 | Portlandite | Henderson D M, Gutowsky H S (1962) A nuclear magnetic resonance determination of the hydrogen positions in Ca(OH)2 American Mineralogist 47 1231-1251 | | 1962 | 0 | 83 | |
| 0009069 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 0.07 | 293 | ||
| 0009070 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 0.15 | 293 | ||
| 0008414 | Portlandite | Nagai T, Ito T, Hattori T, Yamanaka T (2000) Compression mechanism and amorphization of portlandite, Ca(OH)2: structural refinement under pressure Physics and Chemistry of Minerals 27 462-466 | 2000 | 0.5 | 293 | ||
| 0009071 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 0.78 | 293 | ||
| 0009072 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 1.61 | 293 | ||
| 0009073 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 2.08 | 293 | ||
| 0009074 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 2.35 | 293 | ||
| 0008415 | Portlandite | Nagai T, Ito T, Hattori T, Yamanaka T (2000) Compression mechanism and amorphization of portlandite, Ca(OH)2: structural refinement under pressure Physics and Chemistry of Minerals 27 462-466 | 2000 | 2.4 | 293 | ||
| 0009075 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 2.44 | 293 | ||
| 0009076 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 3.4 | 293 | ||
| 0008416 | Portlandite | Nagai T, Ito T, Hattori T, Yamanaka T (2000) Compression mechanism and amorphization of portlandite, Ca(OH)2: structural refinement under pressure Physics and Chemistry of Minerals 27 462-466 | 2000 | 4.3 | 293 | ||
| 0009077 | Portlandite | Xu H, Zhao Y, Zhang J, Hickmott D D, Daemen L L (2007) In situ neutron diffraction study of deuterated portlandite Ca(OD)2 at high pressure and temperature Physics and Chemistry of Minerals 34 223-232 | 2007 | 4.53 | 293 | ||
| 0008417 | Portlandite | Nagai T, Ito T, Hattori T, Yamanaka T (2000) Compression mechanism and amorphization of portlandite, Ca(OH)2: structural refinement under pressure Physics and Chemistry of Minerals 27 462-466 | 2000 | 6.3 | 293 | ||
| 0008418 | Portlandite | Nagai T, Ito T, Hattori T, Yamanaka T (2000) Compression mechanism and amorphization of portlandite, Ca(OH)2: structural refinement under pressure Physics and Chemistry of Minerals 27 462-466 | 2000 | 8.1 | 293 | ||
| 0008419 | Portlandite | Nagai T, Ito T, Hattori T, Yamanaka T (2000) Compression mechanism and amorphization of portlandite, Ca(OH)2: structural refinement under pressure Physics and Chemistry of Minerals 27 462-466 | 2000 | 9.7 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.628 Å | (100) |
| 4.90 Å | (74) |
| 1.927 Å | (42) |
| 1.796 Å | (36) |
| 3.112 Å | (23) |
| 1.687 Å | (21) |
| 1.484 Å | (13) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| 33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) | |
| Stage 7: Great Oxidation Event | <2.4 |
| 45b : [Other oxidized fumarolic minerals] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 50 : Coal and/or oil shale minerals | <0.36 |
| 51 : Pyrometamorphic minerals (see also #54 and #56) | <0.36 |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) | |
| 56 : Slag and smelter minerals (see also #51 and #55) |
Type Occurrence of Portlandite
General Appearance of Type Material:
Microscopic euhedral crystals in cavities.
Place of Conservation of Type Material:
The Natural History Museum, London, England, 1933,307.
Geological Setting of Type Material:
Alteration product of calcium silicates in larnite-spurrite contact metamorphic rocks.
Associated Minerals at Type Locality:
Other Language Names for Portlandite
Relationship of Portlandite to other Species
Member of:
Other Members of Brucite Group:
| Amakinite | Fe2+(OH)2 | Trig. |
| Brucite | Mg(OH)2 | Trig. 3m(32/m) : P3m1 |
| Pyrochroite | Mn(OH)2 | Trig. 3m(32/m) : P3m1 |
| Theophrastite | Ni(OH)2 | Trig. 3m(32/m) : P3m1 |
Common Associates
Associations Based on Photo Data:
| 6 photos of Portlandite associated with Bentorite | Ca6Cr2(SO4)3(OH)12 · 26H2O |
| 6 photos of Portlandite associated with Andradite | Ca3Fe3+2(SiO4)3 |
| 6 photos of Portlandite associated with Ettringite | Ca6Al2(SO4)3(OH)12 · 26H2O |
| 5 photos of Portlandite associated with Oldhamite | CaS |
| 4 photos of Portlandite associated with Quartz | SiO2 |
| 4 photos of Portlandite associated with Fluorite | CaF2 |
| 4 photos of Portlandite associated with Periclase | MgO |
| 4 photos of Portlandite associated with Spurrite | Ca5(SiO4)2(CO3) |
| 3 photos of Portlandite associated with Afwillite | Ca3[SiO4][SiO2(OH)2] · 2H2O |
| 3 photos of Portlandite associated with Thaumasite | Ca3(SO4)[Si(OH)6](CO3) · 12H2O |
Related Minerals - Strunz-mindat Grouping
| 4.FE. | Nannoniite | Al2(OH)5F |
| 4.FE.05 | Brucite | Mg(OH)2 |
| 4.FE.05 | Theophrastite | Ni(OH)2 |
| 4.FE.05 | Amakinite | Fe2+(OH)2 |
| 4.FE.05 | Pyrochroite | Mn(OH)2 |
| 4.FE.10 | Doyleite | Al(OH)3 |
| 4.FE.10 | Bayerite | Al(OH)3 |
| 4.FE.10 | Nordstrandite | Al(OH)3 |
| 4.FE.10 | Gibbsite | Al(OH)3 |
| 4.FE.15 | Lepidocrocite | Fe3+O(OH) |
| 4.FE.15 | Böhmite | AlO(OH) |
| 4.FE.20 | Heterogenite | Co3+O(OH) |
| 4.FE.20 | Grimaldiite | CrO(OH) |
| 4.FE.25 | Lithiophorite | (Al,Li)MnO2(OH)2 |
| 4.FE.25 | Feitknechtite | Mn3+O(OH) |
| 4.FE.30 | Quenselite | PbMnO2(OH) |
| 4.FE.35 | Ferrihydrite | Fe3+10O14(OH)2 |
| 4.FE.40 | Vernadite | (Mn4+,Fe3+,Ca,Na)(O,OH)2 · nH2O |
| 4.FE.40 | Feroxyhyte | Fe3+O(OH) |
| 4.FE.45 | Quetzalcoatlite | Zn6Cu3(TeO6)2(OH)6 · AgxPbyClx+2y |
| 4.FE.50 | Fuettererite | Pb3Cu2+6Te6+O6(OH)7Cl5 |
Other Information
Thermal Behaviour:
In a closed tube it gives off water.
Notes:
Portlandite is slightly water soluble (~1.73 g/L at 20°C), yielding a high pH solution. Portlandite is also soluble in acids and in glycerin; however, it is insoluble in ethanol.
Reacts with clove oil a being gradually stained yellow; the oil itself also develops a yellowish tint. Portlandite is unaffected by mixtures of cedar-wood oil and a-monobromonaphthalene.
Reacts with clove oil a being gradually stained yellow; the oil itself also develops a yellowish tint. Portlandite is unaffected by mixtures of cedar-wood oil and a-monobromonaphthalene.
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 Portlandite
mindat.org URL:
https://www.mindat.org/min-3264.html
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References for Portlandite
Reference List:
Tilleu, C. E. (1933) Portlandite, a new mineral from Scawt Hill, Co. Antrim. Mineralogical Magazine and Journal of the Mineralogical Society, 23 (142) 419-420 doi:10.1180/minmag.1933.023.142.04
Bloss, F. Donald (1969) Indexing powder patterns for cubic materials. American Mineralogist, 54 (5-6) 924-930
Neal, Colin, Stanger, Gordon (1984) Calcium and magnesium hydroxide precipitation from alkaline groundwaters in Oman, and their significance to the process of serpentinization. Mineralogical Magazine, 48 (347) 237-241 doi:10.1180/minmag.1984.048.347.07
Chaix-Pluchery, O., Pannetier, J., Bouillot, J., Niepce, J.C. (1987) Structural prereactional transformations in Ca(OH)2. Journal of Solid State Chemistry, 67. 225-234 doi:10.1016/0022-4596(87)90358-6
Lutz, H.D.; Möller, H.; Schmidt, M. (1994) Lattice vibration spectra. Part LXXXII. Brucite-type hydroxides M(OH)2 (M = Ca, Mn, Co, Fe, Cd) — IR and Raman spectra, neutron diffraction of Fe(OH)2. Journal of Molecular Structure, 328. p.121-132. doi:10.1016/0022-2860(94)08355-x
Localities for Portlandite
Showing 67 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.
Angola | |
| Amores-Casals et al. (2019) |
Australia | |
| Birch (1996) |
Belgium | |
| Nunes (n.d.) |
Canada | |
| Manor et al. (2014) |
| Sokolov S.V. (2010) |
| Rosa et al. (2010) |
China | |
| Zhongtang Yang et al. (2008) +1 other reference |
Czech Republic | |
| Hršelová et al. (2013) |
France | |
| Chollet et al. (2013) |
| XRD analysis (B. Devouard and E. Médard, Clermont-Ferrand) |
| Eytier J.R. & Ch. et al. (2004) |
Germany | |
| Pöllmann (1991) |
| David Nieto collection |
| Bender et al. (1994) |
| Hentschel (1961) |
| in the collection of Christof Schäfer |
| Jasmund et al. (1964) |
| Galuskin et al. (2016) | |
| Wet Chemical by Gerhard Möhn |
| Schüller et al. (1986) |
| Witzke et al. (1998) |
Hungary | |
| Szakáll-Jánosi: Minerals of Hungary |
Israel | |
| Galuskin et al. (2015) |
| Britvin et al. (2026) | |
| Murashko et al. (2025) | |
| Sharygin et al. (2019) | |
| Britvin et al. (2025) |
Italy | |
| Russo et al. (2004) |
| Russo et al. (2004) | |
| Stoppa et al. (2019) |
| Carlini et al. (2018) |
| Passaglia et al. (1982) |
| Rivista Mineralogica Italiana (3) |
| · Ciriotti et al. (2004) +1 other reference |
| Forti et al. (1995) +2 other references |
| Stoppa et al. (2010) +2 other references |
Jordan | |
| Pitty et al. (2010) |
| Sokol et al. (2016) |
| Sokol +9 other references | |
| Khoury et al. (1982) +2 other references |
Mexico | |
| Ward's Natural Science Establishment ... |
Middle East | |
| Gross et al. (1963) +1 other reference | |
Norway | |
| Bancroft et al. (2001) |
Oman | |
| Neal et al. (1984) |
Palestine | |
| Galuskin et al. (2015) |
| Gross (1977) | |
Poland | |
| Łukasz Kruszewski PXRD data |
| Kruszewski (2006) |
Romania | |
| Marincea et al. (2014, September) +1 other reference |
| Marincea +2 other references |
Russia | |
| Pavel M. Kartashov data (2012) |
| Cesnokov et al. (1998) |
| Anthony (1997) |
| Sokolov (2014) |
| Sokolov (2014) |
South Africa | |
| Sokolov S.V. (2010) |
| Cairncross et al. (1995) |
| Pohl et al. (1991) |
| Cairncross et al. (1995) | |
| Speziale et al. (2008) | |
Sweden | |
| Sandström et al. (2010) |
Tajikistan | |
| Sokolov S.V. (2010) +1 other reference |
Tunisia | |
| Dill |
UK | |
| Henmi et al. (1973) +1 other reference |
| Tilleu (1933) +1 other reference |
USA | |
| Roadcap et al. (2005) |
| Dietrich (1990) |
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N'Chwaning I Mine, N'Chwaning Mines, Joe Morolong Local Municipality, John Taolo Gaetsewe District Municipality, Northern Cape, South Africa