- 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:
Just wanted to let you know, I just found your website and it’s a great source of knowledge for someone like me, starting to work in crystallography and advanced characterization techniques. Hope you keep updating, I’ll certainly be looking forward to it.
Hi João, thank you very much for your kind words!
Yes,I will try to update this site more or less regularly!