Tag Archives: Portlandite

Portlandite – basis for a very important building material

Portlandite

  • Named portlandite because it is a common product of hydration of portland cement
  • Formula: Ca(OH)2
  • Space group: P-3m1 (No. 164)
  • Crystal system: trigonal
  • Crystal class: -3 2/m
  • Lattice parameters: a = b = 3.5918 Å, c = 4.9063 Å, α = β = 90°, γ = 120°

Picture (public domain): SEM image of fractured hardened cement paste, showing plates of calcium hydroxide and needles of ettringite


Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • CaO6 octahedra (blue)
  • Oxygen (red)
  • Hydrogen (white)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6ItSG

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#164

#164

P-3m1

Example – Portlandite, Ca(OH)2

Named because the material is a common product of hydration of portland cement.

A nuclear magnetic resonance determination of the hydrogen positions in Ca(OH)2, T = 25 °C

Henderson D M, Gutowsky H S
American Mineralogist 47 (1962) 1231-1251

 

http://www.webmineral.com/data/Portlandite.shtml

CIF
http://rruff.geo.arizona.edu/AMS/download.php?id=00189.cif&down=cif

Portlandite 

CaO6 octahedra (blue)

 

3D rotatable model of Portlandite