Britholite-(Y)
A valid IMA mineral species - grandfathered
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About Britholite-(Y)
Formula:
(Y,Ca)5(SiO4)3OH
Colour:
Reddish-brown, black
Lustre:
Adamantine, Resinous, Dull
Hardness:
5
Specific Gravity:
4.35
Crystal System:
Hexagonal
Member of:
Name:
First described as abukumalite by Hata (1938) from the Suishoyama pegmatite, Fukushima Prefecture, Japan. Later it was renamed as britholite-(Y) as part of the changes in nomenclature for rare-earth minerals (Levinson 1966). It is named for its relation to britholite-(Ce) and the suffix "-(Y)" due to the dominance of yttrium in the composition.
A mineral in the Britholite Group of the Apatite Supergroup. A britholite with predominance of Y among the M site cations and OH > F. The
yttrian analogue of britholite-(Ce). A typically metamict mineral.
yttrian analogue of britholite-(Ce). A typically metamict mineral.
Unique Identifiers
Mindat ID:
776
Long-form identifier:
mindat:1:1:776:2
Similar Names
| Britholite | A synonym of Britholite Group | |
| Britholite-(Ce) | A valid IMA mineral species - grandfathered | (Ce,Ca)5(SiO4)3OH |
| Britholite-(La) | Ca2(La,Ce,Ca)3(SiO4,PO4)3(OH,F) |
IMA Classification of Britholite-(Y)
Approved, 'Grandfathered' (first described prior to 1959)
IMA status notes:
Renamed by the IMA
IMA Formula:
Ca2Y3(SiO4)3OH
First published:
1938
Classification of Britholite-(Y)
9.AH.25
9 : SILICATES (Germanates)
A : Nesosilicates
H : Nesosilicates with CO3, SO4, PO4, etc.
9 : SILICATES (Germanates)
A : Nesosilicates
H : Nesosilicates with CO3, SO4, PO4, etc.
52.4.9.2
52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
4 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] and/or >[6] coordination
52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
4 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] and/or >[6] coordination
17.6.16
17 : Silicates Containing other Anions
6 : Silicates with phosphate
17 : Silicates Containing other Anions
6 : Silicates with phosphate
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Bri-Y | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Bri | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Britholite-(Y)
Adamantine, Resinous, Dull
Transparency:
Transparent, Translucent
Colour:
Reddish-brown, black
Comment:
Yellowish-brown in thin sections.
Streak:
Pale brown
Hardness:
5 on Mohs scale
Tenacity:
Brittle
Cleavage:
Imperfect/Fair
Imperfect on {0001}, {1010}.
Imperfect on {0001}, {1010}.
Fracture:
Irregular/Uneven, Splintery
Density:
4.35 g/cm3 (Measured) 4.44 g/cm3 (Calculated)
Optical Data of Britholite-(Y)
Type:
Uniaxial (-)
RI values:
nω = 1.73 - 1.752 nε = 1.728 - 1.75
Max. Birefringence:
δ = 0.002
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Optical Extinction:
Parallel to cleavage.
Chemistry of Britholite-(Y)
Mindat Formula:
(Y,Ca)5(SiO4)3OH
Element Weights:
Crystallography of Britholite-(Y)
Crystal System:
Hexagonal
Class (H-M):
6/m - Dipyramidal
Space Group:
P63/m
Cell Parameters:
a = 9.43 Å, c = 6.81 Å
Ratio:
a:c = 1 : 0.722
Unit Cell V:
524.45 ų (Calculated from Unit Cell)
Z:
2
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0011045 | Britholite-(Y) | Noe D C, Hughes J M, Mariano A N, Drexler J W, Kato A (1993) The crystal structure of monoclinic britholite-(Ce) and britholite-(Y) Zeitschrift fur Kristallographie 206 233-246 |  | 1993 | Suishoyama, Japan | 0 | 293 |
| 0011044 | Britholite-(Y) | Noe D C, Hughes J M, Mariano A N, Drexler J W, Kato A (1993) The crystal structure of monoclinic britholite-(Ce) and britholite-(Y) Zeitschrift fur Kristallographie 206 233-246 | | 1993 | Suishoyama, Japan | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.813 Å | (100) |
| 2.753 Å | (90) |
| 2.727 Å | (80) |
| 3.13 Å | (50) |
| 3.09 Å | (50) |
| 3.39 Å | (30) |
| 1.885 Å | (30) |
Comments:
Suishoyama pegmatite, Japan.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Britholite-(Y)
Co-Type Localities:
General Appearance of Type Material:
Massive, measuring about 1-2 cm in diameter. Rarely as short prismatic crystals to 3 cm. The outer part of the mineral is always altered into earthy substance of yellowish white or yellowish brown color.
Place of Conservation of Type Material:
Type material destroyed in WWII.
Geological Setting of Type Material:
Granite pegmatite.
Associated Minerals at Type Locality:
Synonyms of Britholite-(Y)
Other Language Names for Britholite-(Y)
Relationship of Britholite-(Y) to other Species
Member of:
Other Members of Britholite Group:
| Britholite-(Ce) | (Ce,Ca)5(SiO4)3OH | Hex. 6/m : P63/m |
| 'Britholite-(La)' | Ca2(La,Ce,Ca)3(SiO4,PO4)3(OH,F) | |
| 'Calciobritholite' | (Ca,Y)5(SiO4,PO4)3(OH) | |
| Fluorbritholite-(Ce) | (Ce,Ca)5(SiO4)3F | Hex. 6/m : P63/m |
| Fluorbritholite-(La) | Ca2La3(SiO4)3F | Hex. 6/m : P63/m |
| Fluorbritholite-(Nd) | Ca2Nd3(SiO4)3F | Hex. 6/m : P63/m |
| Fluorbritholite-(Y) | (Y,Ca)5(SiO4)3F | Hex. 6/m : P63/m |
| Fluorcalciobritholite | (Ca,REE)5(SiO4,PO4)3F | Hex. 6/m : P63/m |
| Tritomite-(Ce) | Ce5(SiO4,BO4)3(OH,O) | |
| Tritomite-(Y) | Y5(SiO4,BO4)3(O,OH,F) |
Common Associates
Associations Based on Photo Data:
| 5 photos of Britholite-(Y) associated with Yttrialite-(Y) | (Y,Th)2Si2O7 |
| 4 photos of Britholite-(Y) associated with Pyrochlore Group | A2Nb2(O,OH)6Z |
| 4 photos of Britholite-(Y) associated with Formanite-(Y) | YTaO4 |
| 4 photos of Britholite-(Y) associated with Allanite-(Ce) | (CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH) |
| 4 photos of Britholite-(Y) associated with 'Yttrofluorite' | (Ca1-xYx)F2+x where 0.05 < x < 0.3 |
| 3 photos of Britholite-(Y) associated with Fluornatropyrochlore | (Na,Pb,Ca,REE,U)2Nb2O6F |
| 2 photos of Britholite-(Y) associated with Zircon | Zr(SiO4) |
| 2 photos of Britholite-(Y) associated with Bastnäsite-(Ce) | Ce(CO3)F |
| 2 photos of Britholite-(Y) associated with Tengerite-(Y) | Y2(CO3)3 · 2-3H2O |
| 1 photo of Britholite-(Y) associated with Fluorapatite | Ca5(PO4)3F |
Related Minerals - Strunz-mindat Grouping
| 9.AH. | Fluorbritholite-(Nd) | Ca2Nd3(SiO4)3F |
| 9.AH.05 | Iimoriite-(Y) | Y2[SiO4][CO3] |
| 9.AH.10 | Tundrite-(Ce) | Na2Ce2Ti(SiO4)(CO3)2O2 |
| 9.AH.10 | Tundrite-(Nd) | Na2(Nd,Ce)2Ti(SiO4)(CO3)2O2 |
| 9.AH.15 | Galuskinite | Ca7(SiO4)3(CO3) |
| 9.AH.15 | Spurrite | Ca5(SiO4)2(CO3) |
| 9.AH.20 | Ternesite | Ca5(SiO4)2(SO4) |
| 9.AH.20 | Silicocarnotite | Ca5[(SiO4)(PO4)](PO4) |
| 9.AH.25 | Britholite-(Ce) | (Ce,Ca)5(SiO4)3OH |
| 9.AH.25 | Mattheddleite | Pb5(SiO4)1.5(SO4)1.5(Cl,OH) |
| 9.AH.25 | Fluorbritholite-(Ce) | (Ce,Ca)5(SiO4)3F |
| 9.AH.25 | Fluorellestadite | Ca5(SiO4)1.5(SO4)1.5F |
| 9.AH.25 | Fluorbritholite-(La) | Ca2La3(SiO4)3F |
| 9.AH.25 | Fluorbritholite-(Y) | (Y,Ca)5(SiO4)3F |
| 9.AH.25 | Hydroxylellestadite | Ca5(SiO4)1.5(SO4)1.5(OH) |
| 9.AH.25 | 'Calciobritholite' | (Ca,Y)5(SiO4,PO4)3(OH) |
| 9.AH.25 | 'Britholite-(La)' | Ca2(La,Ce,Ca)3(SiO4,PO4)3(OH,F) |
| 9.AH.25 | Tritomite-(Ce) | Ce5(SiO4,BO4)3(OH,O) |
| 9.AH.25 | Tritomite-(Y) | Y5(SiO4,BO4)3(O,OH,F) |
| 9.AH.25 | Fluorcalciobritholite | (Ca,REE)5(SiO4,PO4)3F |
| 9.AH.25 | Chlorellestadite | Ca5(SiO4)1.5(SO4)1.5Cl |
| 9.AH.35 | Dargaite | BaCa12(SiO4)4(SO4)2O3 |
| 9.AH.35 | Nabimusaite | KCa12(SiO4)4(SO4)2O2F |
| 9.AH.40 | Stracherite | BaCa6(SiO4)2[(PO4)(CO3)]F |
| 9.AH.40 | Zadovite | BaCa6[(SiO4)(PO4)](PO4)2F |
| 9.AH.40 | Gazeevite | BaCa6(SiO4)2(SO4)2O |
| 9.AH.45 | Flamite | Ca8-x(Na,K)x(SiO4)4-x(PO4)x |
| 9.AH.50 | Byzantievite | Ba5(Ca,REE,Y)22(Ti,Nb)18(SiO4)4[(PO4),(SiO4)]4(BO3)9O22[(OH),F]43(H2O)1.5 |
| 9.AH.55 | Greenwoodite | (Ba,V3+O)2V3+9(Fe3+,Fe2+)2Si2O22 |
| 9.AH.60 | Kihlmanite-(Ce) | Ce2TiO2(SiO4)(HCO3)2(H2O) |
| 9.AH.65 | Tsangpoite | Ca5(PO4)2(SiO4) |
| 9.AH.70 | 'Enalite' | (Th,REE,Al) [(PO4),(SiO4),(OH)] |
Other Information
Notes:
Readily dissolved in cold dilute mineral acids.
Magnetic property is weaker than allanite and greater than yttrialite and xenotime.
Magnetic property is weaker than allanite and greater than yttrialite and xenotime.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Britholite-(Y)
mindat.org URL:
https://www.mindat.org/min-776.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Britholite-(Y)
Reference List:
Omori, Keiichi, Hasegawa, Shuzo (1953) Yttrialite and abukumalite from a pegmatite of Suisho-yama, Iizaka Village, Fukushima Prefecture. The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists, 37 (1) 21-29 doi:10.2465/ganko1941.37.21 [as abukumalite]
Levinson, A. A. (1966) A system of nomenclature for rare-earth minerals. American Mineralogist, 51 (1-2) 152-158
Noe, David C.; Hughes, John M.; Mariano, Anthony N.; Drexler, John W.; Kato, Akira (1993) The crystal structure of monoclinic britholite-(Ce) and britholite-(Y). Zeitschrift für Kristallographie, 206 (1-2). p.233-246. doi:10.1524/zkri.1993.206.12.233
Localities for Britholite-(Y)
Showing 45 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Canada | |
| GSC database +1 other reference |
| Louise Corriveau (Date Modified: 2008-12-08) |
China | |
| Chunliu Song (1988) | |
Finland | |
| Siivola (1975) |
| Jyrki Autio Collection. Pavel M. ... |
| Ilkka Mikkola collection | |
| Pavel M. Kartashov analytical data 2019 |
Japan (TL) | |
| Hata (1938) |
| Nagashima et al. (1971) |
| Sci. Pap. Inst. Phys. Chem. Res. +2 other references |
| ex-Okamoto collection (2015) |
Mongolia | |
| Pavel Kartashov analytical data (2012) |
Norway | |
| Griffin et al. (1979) |
| Husdal et al. (2017) |
| Husdal (2008) |
| Husdal (2008) | |
| Husdal (2008) | |
| Husdal (2008) |
| Husdal (2008) | |
| Neumann (1985) |
Portugal | |
| Lavarde et al. (2019) |
| Knut Edvard Larsen collection |
Russia | |
| ... |
| Попова et al. (2019) |
| Alekseev et al. (2015) |
| Voloshin et al. (2005) +2 other references |
| Pavel M. Kartashov (n.d.) |
| Lunts et al. (1972) | |
| Pavel M. Kartashov (n.d.) | |
| Pavel M. Kartashov collection | |
| Zozulya et al. (2022) | |
| Kalashnikov et al. (2016) | |
Slovakia | |
| Uher et al. (2008) +1 other reference |
South Africa | |
| |
Spain | |
| Sainz de Baranda Graf et al. (2026) |
Sweden | |
| Adamson (1944) +1 other reference |
| Andersson et al. (2024) |
UK | |
| Tindle (2008) | |
| Smith et al. (2002) +2 other references |
USA | |
| Eckel et al. (1997) |
| Eckel et al. (1997) | |
| Demark (2000) |
| Castor et al. (2004) |
| Arthur Smith et al. (2008) |
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West Keivy Block, Western Keivy Massif, Keivy Mountains, Lovozersky District, Murmansk Oblast, Russia