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Seidite-(Ce)
A valid IMA mineral species
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About Seidite-(Ce)
Formula:
Na4(Ce,Sr)2[TiSi8O18(OH)2](O,OH,F)4 · 5H2O
Colour:
Bright yellow, pinkish yellow, creamy-white
Lustre:
Silky
Hardness:
3 - 4
Specific Gravity:
2.76
Crystal System:
Monoclinic
Name:
Named after Seidozero, literally Lake Seid, the central lake in the Lovozero complex.
This page provides mineralogical data about Seidite-(Ce).
Unique Identifiers
Mindat ID:
7284
Long-form identifier:
mindat:1:1:7284:3
Similar Names
IMA Classification of Seidite-(Ce)
Approved
IMA Formula:
Na4(Ce3+,Sr)2Ti4+Si8O18(O,OH,F)6·5H2O
Approval year:
1993
First published:
1998
Classification of Seidite-(Ce)
9.DJ.20
9 : SILICATES (Germanates)
D : Inosilicates
J : Inosilicates with 4-periodic double and triple chains
9 : SILICATES (Germanates)
D : Inosilicates
J : Inosilicates with 4-periodic double and triple chains
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 |
|---|---|---|
| Sei-Ce | 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 Seidite-(Ce)
Silky
Transparency:
Translucent
Comment:
Resinous or dull in some specimens
Colour:
Bright yellow, pinkish yellow, creamy-white
Hardness:
3 - 4 on Mohs scale
Cleavage:
Perfect
Perfect {100} and less perfect {001}
Perfect {100} and less perfect {001}
Fracture:
Splintery, Fibrous
Density:
2.76 g/cm3 (Measured) 2.73 g/cm3 (Calculated)
Optical Data of Seidite-(Ce)
Type:
Biaxial (-)
RI values:
nα = 1.542(2) nβ = 1.569(2) nγ = 1.571(2)
2V:
Measured: 28° (1), Calculated: 31°
Max. Birefringence:
δ = 0.029
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:
Low (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.
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.
Dispersion:
weak
Comments:
positive elongation, X ≈ a, Y ≈ c, Z ≈ b.
Chemistry of Seidite-(Ce)
Mindat Formula:
Na4(Ce,Sr)2[TiSi8O18(OH)2](O,OH,F)4 · 5H2O
Element Weights:
Crystallography of Seidite-(Ce)
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Setting:
P21/m
Cell Parameters:
a = 7.2631(4) Å, b = 24.5294(3) Å, c = 14.3842(6) Å
β = 90.16(5)°
β = 90.16(5)°
Ratio:
a:b:c = 0.296 : 1 : 0.586
Unit Cell V:
2,562.67 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Type material: individual fibers are up to 0.05 mm thick, elongate [010], and flattened {100}.
Comment:
The unit cell designated as rhombic (a = 24.3, b = 7.13, c = 10.74 Å) in the monograph [3] was determined as monoclinic based on electron diffraction data, C2/c, a = 24.61(5) Å, b = 7.23(1) Å, c = 14.53(3) Å, β = 94.6(3)o, V = 2577 Å Refined by . May have 2 polytypes.
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) |
|---|---|---|---|---|---|---|---|
| 0005884 | Seidite-(Ce) | Ferraris G, Belluso E, Gula A, Soboleva S V, Khomyakov A P (2003) The crystal structure of seidite-(Ce), Na4(Ce,Sr)2{Ti(OH)2(Si8O18)}(O,OH,F)4.5H2O, a modular microporous titanosilicate of the rhodesite group The Canadian Mineralogist 41 1183-1192 |  | 2003 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.32 Å | (100) |
| 6.93 Å | (30B) |
| 3.11 Å | (24) |
| 7.22 Å | (20B) |
| 6.20 Å | (20B) |
| 3.23 Å | (20B) |
| 3.08 Å | (16) |
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 Seidite-(Ce)
General Appearance of Type Material:
Bright yellow, pinkish yellow, or cream-colored spherulites to 1 cm, in cavernous natrolite.
Place of Conservation of Type Material:
Museum of the St. Petersburg Mining Institute, Russia.
Geological Setting of Type Material:
Ultraagpaitic pegmatite.
Associated Minerals at Type Locality:
Synonyms of Seidite-(Ce)
Other Language Names for Seidite-(Ce)
Common Associates
Associations Based on Photo Data:
| 6 photos of Seidite-(Ce) associated with Manganoneptunite | KNa2Li(Mn2+)2Ti2[Si4O12]2 |
| 3 photos of Seidite-(Ce) associated with Abellaite | NaPb2(CO3)2(OH) |
| 3 photos of Seidite-(Ce) associated with Galena | PbS |
| 3 photos of Seidite-(Ce) associated with Natrolite | Na2Al2Si3O10 · 2H2O |
| 1 photo of Seidite-(Ce) associated with Raite | Mn2+Mn2+2Na2(◻1.75Ti0.25)Si8O20(OH)2(H2O)4 · Na(H2O)6 |
Related Minerals - Strunz-mindat Grouping
| 9.DJ.05 | Narsarsukite | Na2(Ti,Fe3+)Si4(O,F)11 |
| 9.DJ.10 | Laplandite-(Ce) | Na4CeTiPO4Si7O18 · 5H2O |
| 9.DJ.15 | Caysichite-(Y) | (Ca,Yb,Er)4Y4(Si8O20)(CO3)6(OH) · 7H2O |
| 9.DJ.25 | Carlosturanite | (Mg,Fe,Ti)21(Si,Al)12O28(OH)34 · H2O |
| 9.DJ.30 | Jonesite | Ba4(K,Na)2Ti4Al2(Si3O9)2(SiO4)4O2 · 6H2O |
Fluorescence of Seidite-(Ce)
Nonfluorescent
Other Information
Thermal Behaviour:
The DTA curve has a strong endotherm at 180°C (dehydration) and weak ones at 650, 740, and 840°C (incongruent melting). Weight loss between 20 and 200°C is 8.2%, and total loss to 1000°C is 11.1 wt%. Readily rehydrates after heating to 300°C.
Notes:
Readily soluble in 10% HCl or HNO3, reacts with H2O.
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 Seidite-(Ce)
mindat.org URL:
https://www.mindat.org/min-7284.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Seidite-(Ce)
Reference List:
Khomyakov, A. P., Ferraris, G., Belluso, E., Britvin, S. N., Nechelyustov, G. N., Soboleva, S. V. (1998) Seidite-(Ce), Na4SrCeTiSi8O22F·5H2O, a new mineral with zeolitic properties. Zapiski Vserossijskogo Mineralogicheskogo Obshchestva, 127 (4) 94-100
Jambor, John L., Puziewicz, Jacek, Roberts, Andrew C. (2000) New Mineral Names. American Mineralogist, 85. 627-630
Localities for Seidite-(Ce)
Showing 4 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.
Russia | |
| ... |
| Kasatkin (2019) |
| Mandarino (1996) +2 other references |
USA | |
| Henry Barwood - unpublished (2010) |
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Yubileinaya pegmatite, Karnasurt Mountain, Lovozersky District, Murmansk Oblast, Russia