Churchite-(Y) Mineral Data

General Churchite-(Y) Information

Chemical Formula:

YPO4•2(H2O)

Composition:

Molecular Weight = 219.91 gm

Yttrium 40.43 % Y 51.34 % Y₂O₃

Phosphorus 14.08 % P 32.27 % P₂O₅

Hydrogen 1.83 % H 16.38 % H₂O

Oxygen 43.65 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Y(PO₄)•2(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1865

Locality:

Trefoil mine, near Bodmin, Cornwall, England. Link to MinDat.org Location Data.

Name Origin:

Named for Arthur Hubert Church (1834-19150, English chemist who described and analyzed the mineral.

Name Pronunciation:

Churchite-(Y) + Pronunciation

Synonym:

ICSD 75246

PDF 8-167

Weinschenkite

Churchite-(Y) Image

Images:

Churchite-(Y)

Comments: Acicular, radiating crystals of churchite-(Y).
Location: Leoni mine, Auerbach, Bavaria, Germany. Scale: Size Not Given.
© Lou Perloff / Photo Atlas of Minerals

Churchite-(Y) Crystallography

Axial Ratios:

a:b:c =0.3705:1:0.4088

Cell Dimensions:

a = 5.61, b = 15.14, c = 6.19, Z = 4; beta = 115.3° V = 475.32 Den(Calc)= 3.07

Crystal System:

Monoclinic Space Group: A2/a,Aa

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 4.21(1), 3.02(0.9), 7.5(0.9),

Physical Properties of Churchite-(Y)

Cleavage:

{101} Perfect

Color:

Colorless, Gray, Snow white.

Density:

3.265

Diaphaneity:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Platy - Sheet forms (e.g. micas).

Hardness:

3 - Calcite

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Churchite-(Y)

Gladstone-Dale:

CI meas= 0.034 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.027 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2075,KPDmeas= 0.1951,KC= 0.202
Ncalc = 1.62 - 1.66

Optical Data:

Biaxial (+), a=1.623, b=1.631, g=1.657, bire=0.0340, 2V(Calc)=60, 2V(Meas)=10.

Calculated Properties of Churchite-(Y)

Electron Density:

Bulk Density (Electron Density)=2.96 gm/cc
note: Specific Gravity of Churchite-(Y) =3.07 gm/cc.

Fermion Index:

Fermion Index = 0.0002122846
Boson Index = 0.9997877154

Photoelectric:

PE_{Churchite-(Y)}= 49.96 barns/electron
U=PE_{Churchite-(Y)} x rElectron Density= 147.86 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Churchite-(Y) is Not Radioactive

Churchite-(Y) Classification

Dana Class:

40.04.06.01 (40)Hydrated Phosphates, etc

(40.04)where A+++ XO4 ï¿½ x(H2O)

(40.04.06)Dana Group

40.04.06.01 Churchite-(Y) YPO4•2(H2O) A2/a,Aa Mono

40.04.06.02 Churchite-(Nd)! Nd(PO4)•2(H2O) Mono

Strunz Class:

08.CJ.50 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CJ -With only large cations

08.CJ.50 Ardealite Ca2(SO4)(HPO4)•4(H2O) Cc m

08.CJ.50 Brushite CaHPO4•2(H2O) I2/a 2/m

08.CJ.50 Churchite-(Dy)* (Dy,Sm,Gd,Nd)(PO4)•2(H2O) Mono

08.CJ.50 Churchite-(Nd)! Nd(PO4)•2(H2O) Mono

08.CJ.50 Churchite-(Y) YPO4•2(H2O) A2/a,Aa Mono

08.CJ.50 Pharmacolite CaHAsO4•2(H2O) Ia m

Other Churchite-(Y) Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Churchite-(Y) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - WWW-MINCRYST

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Print or Cut-and-Paste your Churchite-(Y) Specimen Label here :

Churchite-(Y)

YPO4•2(H2O)
Dana No: 40.04.06.01 Strunz No: 08.CJ.50
Locality:

Notes:

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