Constituent
Name
Nobleite
IMA name
Nobleite
Class
non-silicate mineral
Compound type
borate
Constituent abundance in material
Relevance
main - minor
Arrangement
in multi-phases
Mass fraction
0.02 $\pm$ 0.2
Chemical composition
Formula
$CaB_6O_9(OH)_2 \bullet 3(H_2O)$
Chemical formula
CaB6O9(OH)2•3(H2O)
Elemental formula
(Ca2+) B6 O12 H8 (O-)2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Ca^{2+}$ Calcium cation element 1 constituent cation main
$B$ Boron element 6 constituent element main
$O$ Oxygen element 9 constituent element main
$(OH)^-$ Hydroxide anion chemical function 2 anionic radical main
$H_2O$ Water molecule 3 hydration main
Chemical functions
  Function Number Relevance
$(OH)^-$ 2
$R-OH$ 2 main
Chemical bonds
  Bond Number Relevance
$>B-O-$ 12
$\geq B-O-$ 8
$-O-H$ 2 main
$O^--H$ 1
Oxides
Formula $CaO$ $B_{2}O_{3}$ $H_{2}O$
Mass fraction (%) 16.64 61.98 21.38

Strunz

Class
borates (06)
Division
hexaborates (06.F)
Family
Phyllo-hexaborates (06.FC)
Code
06.FC.05

Dana

Major class
carbonates, nitrates, borates (V)
Class
hydrated borates containing hydroxyl or halogen (26)
Type
26.06
Group
-Nobleite- group (26.06.06)
Code
26.06.06.01
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
P2(1)/c
Molar mass
336.99 $g/mol$
Density
2.09 $g/cm^3$
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.054
Refraction index $n_{\alpha}$
1.5
Refraction index $n_{\beta}$
1.52
Refraction index $n_{\gamma}$
1.554
Color
colorless, white
Diaphaneity
transparent
Luster
vitreous