Class

non-silicate mineral

Compound type

phosphate

Chemical functions

	Function	Number	Relevance
	$(PO_4)^{3-}$	1
	$R-OH$	2	main

Chemical bonds

	Bond	Number	Relevance
	$\cdot (\cdot) Y^{3+} \cdot O^{-}-$	3
	$-O \dots H-$	4
	$-O-H$	2	main
	$\dddot - \dddot - \dddot - P \dddot - O^{-3/4}$	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

Texture

polycrystalline

Molar mass

219.91 $g/mol$

Density

3.265 $g/cm^3$

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

Color

colorless, gray, snow white

Diaphaneity

transparent

Luster

vitreous