Constituent
Name
rhonite
IMA name
Rhonite
Class
silicate mineral
Compound type
inosilicate
Constituent abundance in material
Relevance
main - major
Arrangement
heterogeneous in multi-phases
Chemical composition
Formula
$Ca_2(Mg,Fe^{2+},Fe^{3+},Ti)_6(Si,Al)_6O_{20}$
Chemical formula
Ca2(Mg,Fe2+,Fe3+,Ti)6(Si,Al)6O20
Elemental formula
(Ca)1-2 (Mg)2-4 (Fe2+)0-2 (Fe3+)0-2 (Al)1-3 (Ti)0-1 (Si)3-5 O20
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Ca$ Calcium element 1 - 2 constituent element main
$Mg$ Magnesium element 2 - 4 constituent element main
$Fe^{2+}$ Iron(II) cation element 0 - 2 constituent element main
$Fe^{3+}$ Iron(III) cation element 0 - 2 constituent element main
$Al$ Aluminium element 1 - 3 constituent element main
$Ti$ Titanium element 0 - 1 constituent element main
$Si$ Silicon element 3 - 5 constituent element main
$O$ Oxygen element 20 constituent element main
Composition comments
Proportions are very various. Common impurities: K, Na, Mn
Oxides
Formula $K_{2}O$ $Na_{2}O$ $CaO$ $MgO$ $TiO_{2}$ $Al_{2}O_{3}$ $FeO$ $Fe_{2}O_{3}$ $SiO_{2}$
Mass fraction (%)

Strunz

Class
silicates (09)
Division
inosilicate (09.D)
Family
with 4-periodic single chains, Si4O12 (09.DH)
Code
09.DH.45

Dana

Major class
silicates (VIII)
Class
inosilicate chains with side branches or loops (69)
Type
with P>2 (69.02)
Group
Aenigmatite and related species (Aenigmatite subgroup) (69.02.01a)
Code
69.02.01a.05
Phase type
crystalline
Crystal system
triclinic
Crystal class
pinacoidal
Crystal class symbol
-1 (Ci)
Crystal spacegroup
P1
Texture
monocrystalline
Molar mass
814.43 $g/mol$
Density
3.4 - 3.76 $g/cm^3$
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.0350
Refraction index $n_{\alpha}$
1.795 - 1.81
Refraction index $n_{\beta}$
1.806 - 1.825
Refraction index $n_{\gamma}$
1.83 - 1.845
Dispersion V
r > v extreme
Color
brown, black
Diaphaneity
translucent to opaque
Luster
submetallic