Constituent
Name
Ulexite
IMA name
Ulexite
Class
non-silicate mineral
Compound type
borate
Comments
silky in fibrous aggregates
Constituent abundance in material
Relevance
main - major
Arrangement
in multi-phases
Mass fraction
0.12 $\pm$ 0.2
Chemical composition
Formula
$NaCaB_5O_6(OH)_6 \bullet 5(H_2O)$
Chemical formula
NaCaB5O6(OH)6•5(H2O)
Elemental formula
(Na+) (Ca2+) B5 O11 H16 (O-)6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Na^+$ Sodium cation element 1 constituent cation main
$Ca^{2+}$ Calcium cation element 1 constituent cation main
$B$ Boron element 5 constituent element main
$O$ Oxygen element 6 constituent element main
$(OH)^-$ Hydroxide anion chemical function 6 anionic radical main
$H_2O$ Water molecule 5 hydration main
Chemical functions
  Function Number Relevance
$(OH)^-$ 6
$R-OH$ 2 main
Chemical bonds
  Bond Number Relevance
$>B-O-$ 6
$\geq B-O-$ 12
$-O-H$ 2 main
$O^--H$ 1
Oxides
Formula $Na_{2}O$ $CaO$ $B_{2}O_{3}$ $H_{2}O$
Mass fraction (%) 7.65 13.84 42.95 35.57

Strunz

Class
borates (06)
Division
pentaborates (06.E)
Family
Neso-pentaborates (06.EA)
Code
06.EA.25

Dana

Major class
carbonates, nitrates, borates (V)
Class
hydrated borates containing hydroxyl or halogen (26)
Type
26.05
Group
-Ulexite- group (26.05.11)
Code
26.05.11.01
Phase type
crystalline
Crystal system
triclinic
Crystal class
pinacoidal
Crystal class symbol
-1 (Ci)
Crystal spacegroup
P-1
Molar mass
405.23 $g/mol$
Density
1.955 $g/cm^3$
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.030
Refraction index $n_{\alpha}$
1.49
Refraction index $n_{\beta}$
1.51
Refraction index $n_{\gamma}$
1.52
Dispersion V
none
Color
colorless, white
Diaphaneity
translucent
Luster
vitreous