Constituent
Name
Portlandite
IMA name
Portlandite
Class
non-silicate mineral
Compound type
oxide-hydroxide
Relevance
main - major
Arrangement
homogeneous in multi-phases
Formula
Ca(OH)2
Chemical formula
Ca(OH)2
Elemental formula
Ca O2 H2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Ca Calcium element 1 constituent element main
O Oxygen element 1 constituent element main
(OH) Hydroxide anion chemical function 1 anionic radical main
Composition comments
Common impurities: ?
Chemical functions
  Function Number
(OH) 2
Chemical bonds
  Bond Number
OH 1
Oxides
Formula CaO H2O
Mass fraction (%) 975.6 24.31

Strunz

Class
oxides - hydroxides - arsenites (04)
Division
hydroxides (without V or U) (04.F)
Family
Hydroxides with OH, without H2O; sheets of edge-sharing octahedral (04.FE)
Code
04.FE.05

Dana

Major class
oxides and hydroxides (III)
Class
hydroxides and oxides containing hydroxyl (06)
Type
where X++ (OH)2 (06.02)
Group
Brucite group (Rhombohedral: P-3m1) (06.02.01)
Code
06.02.01.04
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
P-3m1
Crystal sites
Label Nb Type Wp Specie Specie coordinence Specie occupancy Specie oxidation state
Ca 1 main 1a-3m.  Ca2+ trigonal prismatic VI 1.0 2
O 2 main 6i.m.  O 1.0 -1
H 6 main 6i.m.  H linear I 0.333
Molar mass
74.09 g/mol
Density
2.227 - 2.233 g/cm3
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.027
Refraction index nα
1.574
Refraction index nβ
1.547
Color
light yellow
Diaphaneity
transparent
Luster
pearly