Natrosilite
A valid IMA mineral species
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About Natrosilite
Formula:
Na2Si2O5
Colour:
Colourless
Lustre:
Pearly
Specific Gravity:
2.48
Crystal System:
Monoclinic
Name:
Derives from the composition, including NATRium (sodium in Latin) and SILIcon.
At least four synthetic dimorphs are known at normal pressure:
α-Na2Si2O5 (orthorhombic; Pant and Cruickshank, 1968);
γ-Na2Si2O5;
δ-Na2Si2O5 (monoclinic; Kahlenberg et al., 1999);
κ-Na2Si2O5 (orthorhombic; Rakić et al., 2003).
α-Na2Si2O5 (orthorhombic; Pant and Cruickshank, 1968);
γ-Na2Si2O5;
δ-Na2Si2O5 (monoclinic; Kahlenberg et al., 1999);
κ-Na2Si2O5 (orthorhombic; Rakić et al., 2003).
Unique Identifiers
Mindat ID:
2863
Long-form identifier:
mindat:1:1:2863:5
IMA Classification of Natrosilite
Approved
Approval year:
1974
First published:
1975
Classification of Natrosilite
9.EE.40
9 : SILICATES (Germanates)
E : Phyllosilicates
E : Single tetrahedral nets of 6-membered rings connected by octahedral nets or octahedral bands
9 : SILICATES (Germanates)
E : Phyllosilicates
E : Single tetrahedral nets of 6-membered rings connected by octahedral nets or octahedral bands
74.3.5.1
74 : PHYLLOSILICATES Modulated Layers
3 : Modulated Layers with joined strips
74 : PHYLLOSILICATES Modulated Layers
3 : Modulated Layers with joined strips
14.1.1
14 : Silicates not Containing Aluminum
1 : Silicates of the alkali metals
14 : Silicates not Containing Aluminum
1 : Silicates of the alkali metals
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 |
|---|---|---|
| Ns | 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 Natrosilite
Pearly
Transparency:
Transparent
Colour:
Colourless
Streak:
White
Cleavage:
Perfect
{100} micaceous (perfect), {001} distinct, {01l} poor.
{100} micaceous (perfect), {001} distinct, {01l} poor.
Density:
2.48 g/cm3 (Measured) 2.51 g/cm3 (Calculated)
Optical Data of Natrosilite
Type:
Biaxial (-)
RI values:
nα = 1.507 nβ = 1.517 nγ = 1.521
2V:
Measured: 49° to 64°, Calculated: 64°
Max. Birefringence:
δ = 0.014
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 (negative)
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:
none
Optical Extinction:
Y ∧ c = -12° to 2°.
Chemistry of Natrosilite
Mindat Formula:
Na2Si2O5
Element Weights:
Elements listed:
Common Impurities:
K,H2O
Crystallography of Natrosilite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/a
Cell Parameters:
a = 12.30(2) Å, b = 4.88(1) Å, c = 8.27(3) Å
β = 104.25°
β = 104.25°
Ratio:
a:b:c = 2.52 : 1 : 1.695
Unit Cell V:
481.12 ų (Calculated from Unit Cell)
Z:
4
Twinning:
Twins on {100}, were noted on synthetic material by Donnay and Donnay.
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) |
|---|---|---|---|---|---|---|---|
| 0009344 | Natrosilite | Pant A K (1968) A reconsideration of the crystal structure of beta-Na2Si2O5 Acta Crystallographica B24 1077-1083 |  | 1968 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.06 Å | (100) |
| 4.17 Å | (60) |
| 3.97 Å | (80) |
| 3.64 Å | (70) |
| 2.98 Å | (90) |
| 2.435 Å | (80) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 9 : Lava/xenolith minerals (hornfels, sanidinite facies) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Natrosilite
General Appearance of Type Material:
Pseudohexagonal thick-tabular crystals to 6 cm in size.
Place of Conservation of Type Material:
Geology Museum, Kola Branch, Academy of Sciences, Apatity, Russia, 3394.
Mining Institute, St.Petersburg, Russia, 1087/1.
A. E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, vis5123, vis5147.
Mining Institute, St.Petersburg, Russia, 1087/1.
A. E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, vis5123, vis5147.
Geological Setting of Type Material:
Pegmatitic segregations of nepheline syenite.
Associated Minerals at Type Locality:
Synonyms of Natrosilite
Other Language Names for Natrosilite
Common Associates
Associations Based on Photo Data:
| 7 photos of Natrosilite associated with Ussingite | Na2AlSi3O8OH |
| 6 photos of Natrosilite associated with Villiaumite | NaF |
| 6 photos of Natrosilite associated with Nordite-(Ce) | (Ce,La)(Sr,Ca)Na2(Na,Mn)(Zn,Mg)Si6O17 |
| 5 photos of Natrosilite associated with Sphalerite | ZnS |
| 3 photos of Natrosilite associated with Vuonnemite | Na11Ti4+Nb2(Si2O7)2(PO4)2O3(F,OH) |
| 3 photos of Natrosilite associated with Microcline | K(AlSi3O8) |
| 2 photos of Natrosilite associated with Manaksite | KNaMnSi4O10 |
| 2 photos of Natrosilite associated with Phosinaite-(Ce) | Na13Ca2(Ce,La,Th,Nd,Pr)(Si4O12)(PO4)4 |
| 1 photo of Natrosilite associated with Sodalite | Na4(Si3Al3)O12Cl |
| 1 photo of Natrosilite associated with Vitusite-(Ce) | Na3(Ce,La,Nd)(PO4)2 |
Related Minerals - Strunz-mindat Grouping
| 9.EE. | Cairncrossite | Sr2Ca7-xNa2x(Si4O10)4(OH)2(H2O)15-x |
| 9.EE.05 | Bementite | Mn7Si6O15(OH)8 |
| 9.EE.07 | Innsbruckite | Mn33(Si2O5)14(OH)38 |
| 9.EE.10 | 'Brokenhillite' | Mn8Si6O15(OH)10 |
| 9.EE.10 | Mcgillite | (Mn,Fe)8Si6O15(OH)8Cl2 |
| 9.EE.10 | Friedelite | Mn2+8Si6O15(OH,Cl)10 |
| 9.EE.10 | Pyrosmalite-(Mn) | Mn2+8Si6O15(OH,Cl)10 |
| 9.EE.10 | Pyrosmalite-(Fe) | Fe2+8Si6O15(OH,Cl)10 |
| 9.EE.15 | Nelenite | Mn2+16As3+3Si12O36(OH)17 |
| 9.EE.15 | Schallerite | Mn2+16As3Si12O36(OH)17 |
| 9.EE.20 | Palygorskite | ◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O |
| 9.EE.20 | Yofortierite | Mn2+Mn2+2Mn2+2◻2Si8O20(OH)2(H2O)4 · 4H2O |
| 9.EE.20 | Windhoekite | Fe3+(Fe3+1.67◻0.33)Ca2◻2Si8O20(OH)2(H2O)4(OH)2 · 6H2O |
| 9.EE.20 | Windmountainite | ◻Fe3+2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O |
| 9.EE.20 | Ikorskyite | KMn3+(Si4O10) · 3H2O |
| 9.EE.20 | Tuperssuatsiaite | Fe3+Fe3+2(Na◻)◻2Si8O20(OH)2(H2O)4 · 2H2O |
| 9.EE.20 | 'Unnamed (Na-Ca-Fe-Silicate-Hydrate)' | NaCa(Fe2+,Al,Mn)5[Si8O19(OH)](OH)7 · 5H2O |
| 9.EE.25 | Sepiolite | Mg4(Si6O15)(OH)2 · 6H2O |
| 9.EE.25 | Loughlinite | Na2Mg3Si6O16 · 8H2O |
| 9.EE.25 | Falcondoite | (Ni,Mg)4Si6O15(OH)2 · 6H2O |
| 9.EE.25 | Kalifersite | (K,Na)5Fe3+7Si20O50(OH)6 · 12H2O |
| 9.EE.30 | Orlymanite | Ca4Mn3Si8O20(OH)6 · 2H2O |
| 9.EE.30 | Tungusite | Ca4Fe2Si6O15(OH)6 |
| 9.EE.30 | Gyrolite | NaCa16Si23AlO60(OH)8 · 14H2O |
| 9.EE.35 | Reyerite | (Na,K)2Ca14(Si,Al)24O58(OH)8 · 6H2O |
| 9.EE.35 | Kodamaite | Na3(Ca5Na)Si16O36(OH)4F2 · (14-x)H2O |
| 9.EE.35 | Truscottite | (Ca,Mn)14Si24O58(OH)8 · 2H2O |
| 9.EE.45 | Makatite | Na2Si4O8(OH)2 · 4H2O |
| 9.EE.50 | Varennesite | Na8Mn2Si10O25(OH,Cl)2 · 12H2O |
| 9.EE.55 | Raite | Mn2+Mn2+2Na2(◻1.75Ti0.25)Si8O20(OH)2(H2O)4 · Na(H2O)6 |
| 9.EE.60 | Intersilite | Na6Mn2+Ti[Si10O24(OH)](OH)3 · 4H2O |
| 9.EE.65 | Zakharovite | Na4Mn5Si10O24(OH)6 · 6H2O |
| 9.EE.65 | Shafranovskite | Na3K2(Mn,Fe,Na)4[Si9(O,OH)27](OH)2 · nH2O |
| 9.EE.70 | Zeophyllite | Ca13Si10O28(OH)2F8 · 6H2O |
| 9.EE.75 | Minehillite | (K,Na)2-3Ca28Zn4Al4Si40O112(OH)16 |
| 9.EE.80 | Fedorite | (Na,K)2-3(Ca4Na3)Si16O38(OH,F)2 · 3.5H2O |
| 9.EE.80 | Martinite | (Na,◻,Ca)12Ca4(Si,S,B)14B2O38(OH,Cl)2F2 · 4H2O |
| 9.EE.80 | Ellingsenite | Na5Ca6Si18O38(OH)13 · 6H2O |
| 9.EE.85 | Lalondeite | (Na,Ca)6(Ca,Na)3Si16O38(F,OH)2 · 3H2O |
Other Information
Notes:
Water soluble. Soluble in weak acids.
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 Natrosilite
mindat.org URL:
https://www.mindat.org/min-2863.html
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References for Natrosilite
Reference List:
Morey, G. W., Bowen, N. L. (1924) The Binary System Sodium Metasilicate-Silica. The Journal of Physical Chemistry, 28 (11). 1167-1179 doi:10.1021/j150245a005
Kracek, F. C. (1930) The System Sodium Oxide-Silica. The Journal of Physical Chemistry, 34 (7). 1583-1598 doi:10.1021/j150313a018
Tilley, C. E. (1933) The ternary system, Na2SiO3 — Na2Si2O5—NaAlSiO4. Zeitschrift für Kristallographie, Mineralogie und Petrographie, 43 (6). 406-421 doi:10.1007/bf02951360
Donnay, Gabrielle, Donnay, J. D. H. (1953) Crystal geometry of some alkali silicates. American Mineralogist, 38 (3-4) 163-171
Grund, Alfred (1954) La structure cristalline du disilicate de soude β˗Na2Si2O5. Bulletin de Minéralogie, 77 (4) 775-785 doi:10.3406/bulmi.1954.4927
KNAPP, W. J., VORST, W. D. (1959) Activities and Structure of Some Melts in the System Na2SiO3-Na2Si2O5. Journal of the American Ceramic Society, 42 (11). 559-562 doi:10.1111/j.1151-2916.1959.tb13573.x
Liebau, F. (1960) Notizen: Die Kristallstrukturen von Li2Si2O5, α-Na2Si2O5 und Ag2Si2O5. Zeitschrift für Naturforschung B, 15. 467 doi:10.1515/znb-1960-0715
Liebau, F. (1961) Untersuchungen an Schichtsilikaten des Formeltyps Am(Si2O5)n. II. Über die Kristallstruktur des α-Na2Si2O5. Acta Crystallographica, 14 (4). 395-398 doi:10.1107/s0365110x61001315
Williamson, J., Glasser, F. P. (1965) Phase Relations in the System Na2Si2O5-SiO2. Science, 148 (3677). 1589-1591 doi:10.1126/science.148.3677.1589
Hoffmann, W.; Fischer, P.; Maier, G. (1966) Neutronenbeugung an Na2Si2O5-, Na2SiO3- und SiO2-Glas und die Additivität der Intensitätsdaten. Die Naturwissenschaften, 53 (1). 16-17 doi:10.1007/bf00607620
Pant, A. K. (1968) A reconsideration of the crystal structure of β-Na2Si2O5. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 24 (8) 1077-1083 doi:10.1107/s0567740868003729
Pant, A. K., Cruickshank, D. W. J. (1968) The crystal structure of α-Na2Si2O5. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 24 (1) 13-19 doi:10.1107/s0567740868001640
Hoffmann, W.; Scheel, H.-J. (1969) Über die γ- und δ-Modifikationen des Natriumdisilikates, Na2Si2O5. Zeitschrift für Kristallographie, 129 (5-6). 396-404 doi:10.1524/zkri.1969.129.5-6.396
Fleischer, Michael, Chao, George Y., Mandarino, Joseph A. (1976) New Mineral Names. American Mineralogist, 61 (3-4) 338-341
Heidemann, D.; Hübert, C.; Schwieger, W.; Grabner, P.; Bergk, K.‐H.; Sarv, P. (1992) 29Si‐ und 23Na‐Festkörper‐MAS‐NMR‐Untersuchungen an Modifikationen des Na2Si2O5. Zeitschrift für anorganische und allgemeine Chemie, 617 (11). 169-177 doi:10.1002/zaac.19926170129
MORTUZA, M. G.; DUPREE, R.; HOLLAND, D. (1998) Journal of Materials Science, 33 (14). 3737-3740 doi:10.1023/a:1004640320451
Kahlenberg, V., Dörsam, G., Wendschuh-Josties, M., Fischer, R.X. (1999) The Crystal Structure of δ-Na2Si2O5. Journal of Solid State Chemistry, 146. 380-386 doi:10.1006/jssc.1999.8365
Kahlenberg, V.; Wendschuh-Josties, M.; Fischer, R. X.; Bauer, H.; Holz, J.; Schimmel, G.; Tapper, A. (2000) X-ray powder diffraction data for δ-Na2Si2O5. Powder Diffraction, 15 (2). 139-141 doi:10.1017/s0885715600011003
de Lucas, Antonio, Rodrı́guez, Lourdes, Lobato, Justo, Sánchez, Paula (2002) Synthesis of crystalline δ-Na2Si2O5 from sodium silicate solution for use as a builder in detergents. Chemical Engineering Science, 57 (3). 479-486 doi:10.1016/s0009-2509(01)00372-4
Kahlenberg, V., Rakić, S., Weidenthaler, C. (2003) Room- and high-temperature single crystal diffraction studies on γ-Na2Si2O5: an interrupted framework with exclusively Q3-units. Zeitschrift für Kristallographie - Crystalline Materials, 218 (6) doi:10.1524/zkri.218.6.421.20727
Rakić, S., Kahlenberg, V., Schmidt, B.C. (2003) Hydrothermal synthesis and structural characterization of κ-Na2Si2O5 and Na1.84K0.16Si2O5. Solid State Sciences, 5 (3) 473-480 doi:10.1016/s1293-2558(03)00020-7
Michalik-Zym, Alicja; Zimowska, Małgorzata; Bahranowski, Krzysztof; Serwicka, Ewa (2007) Layered Sodium Disilicates as Precursors of Mesoporous Silicas. Part I: Optimisation of the Synthesis Procedure of δ-Na2Si2O5 and α-Na2Si2O5. Mineralogia, 38 (2). 151-160 doi:10.2478/v10002-007-0023-8
Michalik-Zym, Alicja; Zimowska, Małgorzata; Bielańska, Elżbieta; Bahranowski, Krzysztof; Serwicka, Ewa (2007) Layered Sodium Disilicates as Precursors of Mesoporous Silicas. Part II: Hydration of δ-Na2Si2O5 and α-Na2Si2O5. Mineralogia, 38 (2). 161-170 doi:10.2478/v10002-007-0024-7
Zubkova, N. V., Pekov, I. V., Pushcharovsky, D. Yu. (2014) A review of crystal chemistry of natural silicates of alkaline elements in the light of new structural data. Mineralogical Magazine, 78 (2) 253-265 doi:10.1180/minmag.2014.078.2.03
Localities for Natrosilite
Showing 7 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 | |
| HORVÁTH et al. (2000) |
Greenland | |
| Andersen et al. (2015) |
Russia | |
| Mikhailova et al. (2022) |
| Pekov (1998) |
| [World of Stones 95:5-6 +4 other references |
| Pekov (2005) |
| Anthony et al. (2000) |
Quick NavTopAbout NatrosiliteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Palitra pegmatite, Karnasurt mine, Karnasurt Mountain, Lovozersky District, Murmansk Oblast, Russia