Mineral phase
IMA name
Churchite-(Y)
Secondary names
Weinschenkite
Class
non-silicate mineral
Compound type
phosphate
Formula
$YPO_4 \bullet 2(H_2O)$
Chemical formula
YPO4•2(H2O)
Elemental formula
(Y3+) P O3 (O-)3 H4
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
$H_2O$ Water molecule 2 hydration main
Chemical functions
  Function Number
$(PO_4)^{3-}$ 1
$R-OH$ 2
Chemical bonds
  Bond Number
$\cdot (\cdot) Y^{3+} \cdot O^{-}-$ 3
$-O \dots H-$ 4
$-O-H$ 2
$\dddot - \dddot - \dddot - P \dddot - O^{-3/4}$ 4
Oxides
Formula $Y_{2}O_{3}$ $P_{2}O_{5}$ $H_{2}O$
Mass fraction (%) 51.34 32.27 16.38

Strunz

Class
phosphates - arsenates - vanadates (08)
Division
phosphates without additional anions, with H2O (08.C)
Family
with only large cations (08.CJ)
Code
08.CJ.50

Dana

Major class
phosphates, arsenates, vanadates (VII)
Class
hydrated phosphates (40)
Type
where A+++ XO4·x(H2O) (40.04)
Group
-Churchite- group (40.04.06)
Code
40.04.06.01
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
C2/c
Molar mass
219.91 $g/mol$
Density
3.265 $g/cm^3$
State NTP
solid
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.0340
Refraction index $n_{\alpha}$
1.623
Refraction index $n_{\beta}$
1.631
Refraction index $n_{\gamma}$
1.657
Pure color
colorless
Color
colorless, gray, snow white
Diaphaneity
transparent
Luster
vitreous