Britholite-(Y) Mineral Data

General Britholite-(Y) Information

Chemical Formula:

(Y,Ca)5(SiO4,PO4)3(OH,F)

Composition:

Molecular Weight = 642.79 gm

Calcium 12.47 % Ca 17.45 % CaO

Yttrium 41.49 % Y 52.69 % Y₂O₃

Silicon 9.83 % Si 21.03 % SiO₂

Phosphorus 3.61 % P 8.28 % P₂O₅

Hydrogen 0.12 % H 1.05 % H₂O

Oxygen 31.74 % O

Fluorine 0.74 % F 0.74 % F

- % F -0.31 % -O=F₂

______ ______

100.00 % 100.93 % = TOTAL OXIDE

Empirical Formula:

Y₃Ca₂(SiO₄)_2.25(PO₄)_0.75(OH)_0.75F_0.25

Environment:

In pegmatites.

IMA Status:

Approved IMA 1966

Locality:

In the Suishoyama pegmatite, near Iisaka, Fukushima Prefecture, Japan Link to MinDat.org Location Data.

Name Origin:

From the Greek for weight, in allusion to its density and the content of Y

Name Pronunciation:

Britholite-(Y) + Pronunciation

Synonym:

Abukumalite

ICSD 33858

PDF 31-315

Britholite-(Y) Image

Images:

Britholite-(Y)

Comments: Brown cm-size britholite-(Y) grains with typical prismatic 'apatite' outline in quartz matrix with black magnetite. Tengerite-(Y) forms the white encrustation in upper right part of the photo.
Location: West Keivy Block, Western Keivy Massif, Kola peninsula, Murmanskaja Oblast', Northern Region, Russia. Scale: Picture Size 3.5x3.5 cm.
© Pavel M. Kartashov

Britholite-(Y) Crystallography

Axial Ratios:

a:c = 1:0.72216

Cell Dimensions:

a = 9.43, c = 6.81, Z = 2; V = 524.45 Den(Calc)= 4.07

Crystal System:

Hexagonal - Dipyramidal H-M Symbol (6/m) Space Group: P 6₃/m

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

By Intensity(I/I_o): 2.81(1), 2.75(0.9), 2.73(0.8),

Physical Properties of Britholite-(Y)

Cleavage:

{0001} Imperfect, {1010} Imperfect

Color:

Reddish brown, Black.

Density:

4.25

Diaphaneity:

Translucent to Opaque

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5 - Apatite

Luster:

Resinous

Streak:

pale brown

Optical Properties of Britholite-(Y)

Gladstone-Dale:

CI meas= 0.079 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.038 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1818,KPDmeas= 0.1741,KC= 0.189
Ncalc = 1.77 - 1.8

Optical Data:

Uniaxial (-), e=1.728-1.75, w=1.73-1.752, bire=0.0020.

Calculated Properties of Britholite-(Y)

Electron Density:

Bulk Density (Electron Density)=3.86 gm/cc
note: Specific Gravity of Britholite-(Y) =4.07 gm/cc.

Fermion Index:

Fermion Index = 0.0049118745
Boson Index = 0.9950881255

Photoelectric:

PE_{Britholite-(Y)}= 53.53 barns/electron
U=PE_{Britholite-(Y)} x rElectron Density= 206.58 barns/cc.

Radioactivity:

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

Britholite-(Y) Classification

Dana Class:

52.04.09.02 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.04)with cations in [6] and/or > [6] coordination

(52.04.09)Silicate apatites

52.04.09.00 Ellestadite* Ca5(SiO4,PO4,SO4)3(F,OH,Cl) P 6₃/m 6/m

52.04.09.01 Britholite-(Ce) (Ce,Ca,Th,La,Nd)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

52.04.09.02 Britholite-(Y) (Y,Ca)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

52.04.09.03 Ellestadite-(F) Ca5(SiO4,PO4,SO4)3(F,OH,Cl) P 6₃/m 6/m

52.04.09.04 Ellestadite-(OH) Ca5(SiO4,SO4)3(OH,Cl,F) P 6₃/m 6/m

52.04.09.05 Ellestadite-(Cl) Ca5(SiO4,PO4,SO4)3(Cl,OH,F) P 6₃/m 6/m

52.04.09.06 Mattheddleite Pb20(SiO4)7(SO4)4Cl4 P 6₃/m 6/m

52.04.09.07 Karnasurtite-(Ce) (Ce,La,Th)(Ti,Nb)(Al,Fe)(Si,P)2O7(OH)4•3(H2O)(?) Unk. Hex

52.04.09.08 Fluorbritholite-(Ce) (Ca,Ce,La,Na)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

52.04.09.09 Fluorcalciobritholite! (Ca,REE)5[(Si,P)O4]3F P 6₃/m 6/m

Strunz Class:

09.AH.25 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AH -Nesosilicates with CO3, SO4, PO4, etc.

09.AH.25 Britholite-(Ce) (Ce,Ca,Th,La,Nd)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

09.AH.25 Britholite-(Y) (Y,Ca)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

09.AH.25 Ellestadite-(Cl) Ca5(SiO4,PO4,SO4)3(Cl,OH,F) P 6₃/m 6/m

09.AH.25 Fluorbritholite-(Ce) (Ca,Ce,La,Na)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

09.AH.25 Ellestadite-(F) Ca5(SiO4,PO4,SO4)3(F,OH,Cl) P 6₃/m 6/m

09.AH.25 Ellestadite* Ca5(SiO4,PO4,SO4)3(F,OH,Cl) P 6₃/m 6/m

09.AH.25 Ellestadite-(OH) Ca5(SiO4,SO4)3(OH,Cl,F) P 6₃/m 6/m

09.AH.25 Fluorcalciobritholite! (Ca,REE)5[(Si,P)O4]3F P 6₃/m 6/m

Other Britholite-(Y) Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Britholite-(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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Britholite-(Y)

(Y,Ca)5(SiO4,PO4)3(OH,F)
Dana No: 52.04.09.02 Strunz No: 09.AH.25
Locality:

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