Mineral phase
IMA name
Bastnäsite-(La)
Secondary names
Bastnaesite-(La)
IMA Code
Bsn-La
Type
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
Formula
$La(CO_3)F$
Chemical formula
La(CO3)F
Elemental formula
(La3+) C O (O-)2 (F-)
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$La^{3+}$ Lanthanum cation element 1 constituent cation main
$(CO_3)^{2-}$ Carbonate anion chemical function 1 anionic radical main
$F^-$ Fluoride anion element 1 constituent anion main
Composition comments
La frequently partly substituted by Ce
Chemical functions
  Function Number
$(CO_3)^{2-}$ 1
Chemical bonds
  Bond Number
$\cdot (\cdot) La^{3+} \cdot O^{-}-$ 2
$\cdot (\cdot) La^{3+} \cdot F^{-}$ 1
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $La_{2}O_{3}$ $CO_{2}$ $F$
Mass fraction (%) 74.76 20.2 8.72
Oxides comments
-3.67 % -O=F2

Strunz

Class
carbonates - nitrates (05)
Division
carbonates with additional anions, without H2O (05.B)
Family
with rare-earth elements (REE) (05.BD)
Code
05.BD.20a

Dana

Major class
carbonates, nitrates, borates (V)
Class
carbonates - hydroxyl or halogen (16a)
Type
in the Bastnasite/Shynchysite/Parasite group (16a.01)
Group
Bastnasite subgroup (16a.01.01)
Code
16a.01.01.02
Phase type
crystalline
Crystal system
hexagonal
Crystal class
ditrigonal-dipyramidal
Crystal class symbol
-6m2 (D3h)
Crystal spacegroup
P-62c
Molar mass
217.91 $g/mol$
Density
4.95 - 5 (calc: 4.89) $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
positive
Birefringence
0.101
Refraction index $n_o$ (w)
1.717
Refraction index $n_e$ (e)
1.818
Pure color
yellow
Color
yellow, reddish brown
Diaphaneity
transparent to translucent
Luster
vitreous
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