Constituent
Name
Alpha-CrOOH (synthetic grimaldiite)
Official name
Chromium hydroxide oxide
Family
covalent network solid
Class
tridimentional covalent network solid
Compound type
oxide-hydroxide
Constituent abundance in material
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Mole fraction
1.0
Chemical composition
Formula
$Cr_2O_3$
Chemical formula
Cr(OH)O
Elemental formula
Cr O2 H
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$Cr$ Chromium element 1 0.25 1 constituent element main
$O$ Oxygen element 2 0.5 1 constituent element main
$H$ Hydrogen element 1 0.25 1 constituent element main
Chemical bonds
  Bond Number
$>Cr-O$ 2
$-O-H$ 1
$-O \dots H-$ 1
Class
sheet covalent networks (10)
Type
one metal and one non-metal atoms sheet networks (10.04)
Phase name
alpha-CrOOH
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3m
Comments
Layer crystal structure, where close-packed CrO,-octahedra are held together by short hydrogen bonds.
Texture
polycrystalline
Molar mass
85.00 $g/mol$
Density
4.11 $g/cm^3$
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.18
Refraction index $n_{\alpha}$
2.155
Refraction index $n_{\beta}$
1.975
Color
dark red
Diaphaneity
opaque
Luster
metallic