Constituent
Name
Pinnoite
IMA name
Pinnoite
Class
non-silicate mineral
Compound type
borate
Constituent abundance in material
Relevance
main - major
Arrangement
in multi-phases
Mass fraction
0.13 $\pm$ 0.2
Chemical composition
Formula
$MgB_2O_4 \bullet 3(H_2O)$
Chemical formula
MgB2O4•3(H2O)
Elemental formula
Mg B2 O7 H6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mg$ Magnesium element 1 constituent element main
$B$ Boron element 2 constituent element main
$O$ Oxygen element 4 constituent element main
$H_2O$ Water molecule 3 hydration main
Chemical functions
  Function Number Relevance
$R-OH$ 2 main
Chemical bonds
  Bond Number Relevance
$\geq B-O-$ 8
$-O-H$ 2 main
Oxides
Formula $MgO$ $B_{2}O_{3}$ $H_{2}O$
Mass fraction (%) 24.58 42.46 32.96

Strunz

Class
borates (06)
Division
diborates (06.B)
Family
Neso-diborates with double tetrahedra B2O(OH)6; 2(2T) (06.BB)
Code
06.BB.05

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous borates containing hydroxyl or halogen (25)
Type
25.02
Group
-Pinnoite- group (25.02.03)
Code
25.02.03.01
Phase type
crystalline
Crystal system
tetragonal
Crystal class
pyramidal
Crystal class symbol
4 (C4)
Crystal spacegroup
P4(2)
Molar mass
163.97 $g/mol$
Density
2.29 $g/cm^3$
Refringence type
uniaxial
Refringence sign
positive
Birefringence
0.010
Refraction index $n_{\alpha}$
1.565
Refraction index $n_{\beta}$
1.575
Color
colorless, yellow, yellow green, light yellow
Diaphaneity
translucent
Luster
vitreous