Rowlandite-(Y)
A valid IMA mineral species - grandfathered
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About Rowlandite-(Y)
Henry Augustus Rowland
Formula:
(Y,Ce)4Fe2+(Si2O7)2F2 (?)
Colour:
Pale dull green, greyish white
Lustre:
Vitreous, Waxy
Hardness:
5½ - 6½
Specific Gravity:
4.33 (Calculated)
Crystal System:
Triclinic
Name:
Named in honor of Henry Augustus Rowland (27 November 1848, Honesdale, Pennsylvania, USA - 16 April 1901, Baltimore, Maryland, USA), Professor of Physics, Johns Hopkins University, Baltimore, Maryland, for his spectrographic work on rare-earth elements. He is also known for developing a diffraction grating that now bears his name. Originally named simply rowlandite, the suffix was added in 1987 to denote the dominant rare earth element.
Type Locality:
Unique Identifiers
Mindat ID:
3467
Long-form identifier:
mindat:1:1:3467:4
Similar Names
| Rilandite | A valid IMA mineral species - grandfathered - questionable | Cr6SiO11 · 5H2O (?) |
| Rollandite | A valid IMA mineral species | Cu3(AsO4)2 · 4H2O |
IMA Classification of Rowlandite-(Y)
Approved, 'Grandfathered' (first described prior to 1959)
IMA status notes:
Renamed by the IMA
IMA Formula:
Fe2+Y4(Si2O7)2F2
First published:
1891
Type description reference:
Classification of Rowlandite-(Y)
9.HG.20
9 : SILICATES (Germanates)
H : Unclassified silicates
G : With REE, Th
9 : SILICATES (Germanates)
H : Unclassified silicates
G : With REE, Th
55.2.1b.1
55 : SOROSILICATES Si2O7 Groups,Generally with no Additional Anions
2 : Si2O7 Groups, Generally with no Additional Anions with cations in [6] coordination
55 : SOROSILICATES Si2O7 Groups,Generally with no Additional Anions
2 : Si2O7 Groups, Generally with no Additional Anions with cations in [6] coordination
17.1.18
17 : Silicates Containing other Anions
1 : Silicates with fluoride (not containing Al)
17 : Silicates Containing other Anions
1 : Silicates with fluoride (not containing Al)
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Row-Y | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Rowlandite-(Y)
Vitreous, Waxy
Transparency:
Transparent
Comment:
Waxy when altered
Colour:
Pale dull green, greyish white
Comment:
alters to brick red
Hardness:
5½ - 6½ on Mohs scale
Density:
4.33 g/cm3 (Calculated)
Comment:
4.30 - metamict, 4.55 when heated to 050 for hour, 4.85 when crystalline
Optical Data of Rowlandite-(Y)
Type:
Biaxial (+)
RI values:
nα = 1.763 nγ = 1.769
Max. Birefringence:
δ = 0.006
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 biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
No measured or calculated 2V is on file for this mineral, so the value used here (90°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
No measured or calculated 2V is on file for this mineral, so the value used here (90°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Comments:
Isotropic when metamict (n=1.704; 1.76 when heated)
Chemistry of Rowlandite-(Y)
Mindat Formula:
(Y,Ce)4Fe2+(Si2O7)2F2 (?)
Crystallography of Rowlandite-(Y)
Crystal System:
Triclinic
Cell Parameters:
a = 6.59 Å, b = 8.65 Å, c = 5.53 Å
α = 99.03°, β = 104.12°, γ = 91.47°
α = 99.03°, β = 104.12°, γ = 91.47°
Ratio:
a:b:c = 0.762 : 1 : 0.639
Unit Cell V:
301.24 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Small irregular masses.
Comment:
Commonly metamict.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites |
Geological Setting:
Rare earth bearing pegmatites
Type Occurrence of Rowlandite-(Y)
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
Rare earth pegmatite.
Associated Minerals at Type Locality:
Other Language Names for Rowlandite-(Y)
Dutch:Rowlandiet-(Y)
German:Rowlandit-(Y)
Common Associates
Associations Based on Photo Data:
| 2 photos of Rowlandite-(Y) associated with Gadolinite-(Y) | Y2Fe2+Be2Si2O10 |
| 2 photos of Rowlandite-(Y) associated with 'Yttrofluorite' | (Ca1-xYx)F2+x where 0.05 < x < 0.3 |
| 1 photo of Rowlandite-(Y) associated with Lusernaite-(Y) | Y4Al(CO3)2(OH)10F · 6H2O |
Related Minerals - Strunz-mindat Grouping
| 9.HG.15 | Umbozerite | Na3Sr4Th[Si(O,OH)3-4]8 |
| 9.HG.20 | Mendeleevite-(Nd) | Cs6(Nd,REE,Ca)30(Si70O175)(OH,F,H2O)35 |
| 9.HG.20 | Mendeleevite-(Ce) | Cs6(Ce,REE,Ca)30(Si70O175)(OH,F,H2O)35 |
Other Information
Notes:
Commonly metamict
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 Rowlandite-(Y)
mindat.org URL:
https://www.mindat.org/min-3467.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Rowlandite-(Y)
Reference List:
Frondel, Clifford (1961) Two yttrium minerals; spencite and rowlandite. The Canadian Mineralogist, 6 (5). 576-581
Localities for Rowlandite-(Y)
Showing 12 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 | |
| www.minsocam.org/msa/Handbook/RowlanditeY.PDF. (reference unsubstantiated) |
Finland | |
| Siivola (1975) |
Kazakhstan | |
Norway | |
| Husdal (2008) |
| Husdal (2019) +1 other reference |
| Husdal (2008) +1 other reference | |
| Larsen (2017) +1 other reference |
Romania | |
| HÎRTOPANU et al. (2014) |
Sweden | |
| Berg & Mineral 9 (23) |
USA | |
| Eckel et al. (1997) |
| Crook et al. (1977) +1 other reference |
| Landes (1932) +2 other references |
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Hundholmen, Narvik, Nordland, Norway