Mineral phase
IMA name
Xenotime-(Y)
Type
Class
non-silicate mineral
Compound type
phosphate
Chemical composition
Formula
$YPO_4$
Chemical formula
YPO4
Elemental formula
(Y3+) P O (O-)3
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Y^{3+}$ Yttrium cation element 1 constituent cation main
$(PO_4)^{3-}$ Phosphate anion chemical function 1 anionic radical main
Chemical functions
  Function Number
$(PO_4)^{3-}$ 1
Chemical bonds
  Bond Number
$\cdot (\cdot) Y^{3+} \cdot O^{-}-$ 3
$\dddot - \dddot - \dddot - P \dddot - O^{-3/4}$ 4
Oxides
Formula $Y_{2}O_{3}$ $P_{2}O_{5}$
Mass fraction (%) 61.4 38.6

Strunz

Class
phosphates - arsenates - vanadates (08)
Division
phosphates, etc. without additional anions, without H2O (08.A)
Family
with only large cations (08.AD)
Code
08.AD.35

Dana

Major class
phosphates, arsenates, vanadates (VII)
Class
anhydrous phosphates (38)
Type
A+ XO4 (38.04)
Group
Zenotime group (Tetragonal: I41/amd) (38.04.11)
Code
38.04.11.01
Phase type
crystalline
Crystal system
tetragonal
Crystal class
ditetragonal-dipyramidal
Crystal class symbol
4/mmm (D4h)
Crystal spacegroup
I4(1)/amd
Molar mass
183.88 $g/mol$
Density
4.4 - 5.1 $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
positive
Birefringence
0.095
Refraction index $n_o$ (w)
1.721
Refraction index $n_e$ (e)
1.816
Pure color
brown
Color
yellowish brown, greenish brown, gray, reddish brown, brown
Diaphaneity
opaque
Luster
vitreous
Links