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Magadiite

A valid IMA mineral species
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06045710017271924787363.jpg
Magadiite

Lake Magadi, Kajiado County, Kenya
04805020017271924817584.jpg
Magadiite, etc.

Aris Quarries, Aris, Windhoek Rural, Khomas Region, Namibia
04949270017271924848118.jpg
Magadiite

Demix-Varennes quarry, Saint-Amable sill, Varennes & St-Amable, Lajemmerais RCM, Montérégie, Québec, Canada
06045710017271924787363.jpg
Magadiite

Lake Magadi, Kajiado County, Kenya
04805020017271924817584.jpg
Magadiite, etc.

Aris Quarries, Aris, Windhoek Rural, Khomas Region, Namibia
04949270017271924848118.jpg
Magadiite

Demix-Varennes quarry, Saint-Amable sill, Varennes & St-Amable, Lajemmerais RCM, Montérégie, Québec, Canada
01587010017271924913006.jpg
Magadiite

Lake Magadi, Kajiado County, Kenya
04805020017271924817584.jpg
Magadiite, etc.

Aris Quarries, Aris, Windhoek Rural, Khomas Region, Namibia
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About MagadiiteHide

02988710017271924946655.jpg
Lake Magadi, Kenya

Lake Magadi, Kajiado County, Kenya
Formula:
Na2Si14O29 · 11H2O
Colour:
White
Hardness:
2
Specific Gravity:
2.25 (Calculated)
Crystal System:
Orthorhombic
Name:
Named for the type locality Lake Magadi.
This page provides mineralogical data about Magadiite.


Unique IdentifiersHide

Mindat ID:
2530
Long-form identifier:
mindat:1:1:2530:6

Similar NamesHide

MakatiteA valid IMA mineral speciesNa2Si4O8(OH)2 · 4H2O

IMA Classification of MagadiiteHide

Classification of MagadiiteHide

Strunz-mindat (2026):
9.EA.20

9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
Dana 8th ed.:
78.7.12.1

78 : Unclassified Silicates
7 :
Hey's CIM Ref.:
14.1.5

14 : Silicates not Containing Aluminum
1 : Silicates of the alkali metals

Mineral SymbolsHide

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.

SymbolSourceReference for Standard
MgdIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43
MgdWarr (2020)Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30

Physical Properties of MagadiiteHide

Transparency:
Translucent, Opaque
Colour:
White
Streak:
White
Hardness:
2 on Mohs scale
Comment:
Tenacity: Puttylike
Density:
2.25 g/cm3 (Calculated)

Optical Data of MagadiiteHide

Type:
Biaxial
RI values:
nα = 1.47
Surface Relief:
Unknown
Dispersion:
relatively weak

Chemistry of MagadiiteHide

Mindat Formula:
Na2Si14O29 · 11H2O
Element Weights:
Element% weight
O58.110 %
Si35.702 %
Na4.175 %
H2.014 %

Calculated from ideal end-member formula.
O
Si
Na
H
Elements listed:
H, Na, O, Si - search for minerals with similar chemistry
Common Impurities:
Ti,Al,Fe,Mn,Mg,Ca,K

Crystallography of MagadiiteHide

Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Space Group:
Fdd2
Cell Parameters:
a = 10.5035(9) Å, b = 10.0262(9) Å, c = 61.9608(46) Å
Ratio:
a:b:c = 1.048 : 1 : 6.18
Unit Cell V:
6,525.10 ų (Calculated from Unit Cell)
Morphology:
Putty-like laminae to very thin platy.
Comment:
Space Group: F2dd; Z undetermined

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0012231MagadiiteGarces J M, Rocke S C, Crowder C E, Hasha D L (1988) Hypothetical structures of magadiite and sodium octosilicate and structural relationships between the layered alkali metal silicates and the mordenite- and pentasil-group zeolites Clays and Clay Minerals 36 409-41819880293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
15.41 Å(100)
3.44 Å(80)
3.146 Å(50)
3.30 Å(35)
5.18 Å(19)
4.46 Å(18)
5.01 Å(16)
Comments:
Lake Magadi, Kenya. The data are from the type description.

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 3a: Earth’s earliest Hadean crust>4.50
10 : Basalt-hosted zeolite minerals
Stage 3b: Earth’s earliest hydrosphere>4.45
14 : Hot springs, geysers, and other subaerial geothermal minerals
16 : Low-? aqueous alteration of Hadean subaerial lithologies (see also #23)
Near-surface Processes
25 : Evaporites (prebiotic)
Stage 4b: Highly evolved igneous rocks>3.0
35 : Ultra-alkali and agpaitic igneous rocks

Type Occurrence of MagadiiteHide

Type Locality:
ⓘ Lake Magadi, Kajiado County, Kenya
General Appearance of Type Material:
White putty-like laminae, in beds varying in thickness from 5 cm to 60 cm.
Place of Conservation of Type Material:
National School of Mines, Paris, France.
National Museum of Natural History, Washington, D.C., USA, 121336.
Geological Setting of Type Material:
Evaporite from saline brine.
Associated Minerals at Type Locality:
CalciteKenyaite
Reference:
Eugster, H. P. (1967) Hydrous Sodium Silicates from Lake Magadi, Kenya: Precursors of Bedded Chert. Science, 157 (3793). 1177-1180 doi:10.1126/science.157.3793.1177

Synonyms of MagadiiteHide

Other Language Names for MagadiiteHide

Common AssociatesHide

Associations Based on Photo Data:
5 photos of Magadiite associated with KenyaiteNa2Si22O41(OH)8 · 6H2O
3 photos of Magadiite associated with StishoviteSiO2
3 photos of Magadiite associated with CoesiteSiO2
3 photos of Magadiite associated with MicroclineK(AlSi3O8)
2 photos of Magadiite associated with VarennesiteNa8Mn2Si10O25(OH,Cl)2 · 12H2O
2 photos of Magadiite associated with SilhydriteSi3O6 · H2O
1 photo of Magadiite associated with AegirineNaFe3+Si2O6
1 photo of Magadiite associated with QuartzSiO2
1 photo of Magadiite associated with CalciteCaCO3
1 photo of Magadiite associated with PectoliteNaCa2Si3O8(OH)

Related Minerals - Strunz-mindat GroupingHide

9.EA.Hydroxymcglassonite-(K)KSr4Si8O20(OH) · 8H2OTet.
9.EA.Miyawakiite-(Y)◻Y4Fe2(Si8O20)(CO3)4(H2O)3Tet. 4/mmm(4/m2/m2/m) : I4/mcm
9.EA.Bussyite-(Y)(Y,REE,Ca)3(Na,Ca)6MnSi9Be5(O,OH,F)34Mon. 2 : B2
9.EA.Hydroxyapophyllite-(NH4)(NH4)Ca4(Si8O20)(OH)(H2O)8Tet. 4/mmm(4/m2/m2/m)
9.EA.Fluorapophyllite-(NH4)NH4Ca4(Si8O20)F · 8H2OTet. 4/mmm(4/m2/m2/m) : P4/mnc
9.EA.05GillespiteBaFe2+Si4O10Tet. 4/mmm(4/m2/m2/m) : P4/ncc
9.EA.05CuprorivaiteCaCuSi4O10Tet. 4/mmm(4/m2/m2/m) : P4/ncc
9.EA.05WesselsiteSrCuSi4O10Tet. 4/mmm(4/m2/m2/m) : P4/ncc
9.EA.05EffenbergeriteBaCuSi4O10Tet. 4/mmm(4/m2/m2/m) : P4/ncc
9.EA.07Fluorapophyllite-(Cs)CsCa4(Si8O20)F · 8H2OTet. 4/mmm(4/m2/m2/m) : P4/mnc
9.EA.10EkaniteCa2ThSi8O20Tet. 422 : I422
9.EA.15Fluorapophyllite-(Na)NaCa4(Si8O20)F · 8H2OOrth.
9.EA.15Fluorapophyllite-(K)KCa4(Si8O20)(F,OH) · 8H2OTet. 4/mmm(4/m2/m2/m) : P4/mnc
9.EA.15Hydroxyapophyllite-(K)KCa4(Si8O20)(OH,F) · 8H2OTet. 4/mmm(4/m2/m2/m)
9.EA.25DalyiteK2ZrSi6O15Tric. 1 : P1
9.EA.25DavaniteK2TiSi6O15Tric.
9.EA.30Sazhinite-(La)Na3La[Si6O15] · 2H2OOrth. mm2 : Pmm2
9.EA.30Sazhinite-(Ce)Na3CeSi6O15 · 2H2OOrth. mm2 : Pmm2
9.EA.35ArmstrongiteCaZr[Si6O15] · 3H2OMon. 2/m : B2/m
9.EA.40OkeniteCa10Si18O46 · 18H2OTric. 1 : P1
9.EA.45Perettiite-(Y)Y2Mn4FeSi2B8O24Orth. mmm(2/m2/m2/m) : Pmna
9.EA.45NekoiteCa3Si6O15 · 7H2OTric. 1 : P1
9.EA.45Badakhshanite-(Y)Y2Mn4Al(Si2B7BeO24)Orth. mmm(2/m2/m2/m) : Pnma
9.EA.47ShlykoviteKCa[Si4O9(OH)] · 3H2OMon. 2/m : P21/c
9.EA.50DiegogattaiteNa2CaCu2Si8O20 · H2OMon. 2/m : B2/m
9.EA.50CavansiteCa(VO)Si4O10 · 4H2OOrth. mmm(2/m2/m2/m)
9.EA.52YangitePbMnSi3O8 · H2OTric. 1 : P1
9.EA.55PentagoniteCa(VO)Si4O10 · 4H2OOrth. mm2
9.EA.60PenkvilksiteNa4Ti2Si8O22 · 4H2OOrth. mmm(2/m2/m2/m) : Pbcn
9.EA.60TumchaiteNa2Zr(Si4O11) · 2H2OMon. 2/m : P21/c
9.EA.65NabesiteNa2BeSi4O10 · 4H2OOrth. 222 : P212121
9.EA.70Ajoite(K,Na)Cu7AlSi9O24(OH)6 · 3H2OTric.
9.EA.75ZeravshaniteNa2Cs4Zr3[Si18O45]*2H2OMon. 2/m : B2/b
9.EA.80Bussyite-(Ce)(Ce,REE)3(Na,H2O)6MnSi9Be5(O,OH)30F4Mon. 2/m : B2/b
9.EA.85PlumbophyllitePb2Si4O10 · H2OOrth. mmm(2/m2/m2/m) : Pbcn

Other InformationHide

Notes:
Magadiite in dilute acid at room temperature produces a hydrous form of silica. Subsequent treatment of the silica with concentrated solutions of Na2CO3 or NaOH produces magadiite again.
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 MagadiiteHide

References for MagadiiteHide

Reference List:
Eugster, H. P. (1967) Hydrous Sodium Silicates from Lake Magadi, Kenya: Precursors of Bedded Chert. Science, 157 (3793). 1177-1180 doi:10.1126/science.157.3793.1177
McAtee, J. L., House, R., Eugster, H. P. (1968) Magadiite from Trinity County, California. American Mineralogist, 53 (11-12) 2061-2069
Bricker, Owen P. (1969) Stability constants and Gibbs free energies of formation of magadiite and kenyaite. American Mineralogist, 54 (7-8) 1026-1033
Rooney, Thomas P, Jones, Blair, F., Neal, James T. (1969) Magadiite from Alkali Lake, Oregon. American Mineralogist, 54 (7-8) 1034-1043
Brindley, G. W. (1969) Unit cell of magadiite in air, in vacuo and under other conditions. American Mineralogist, 54 (11-12) 1583-1591
Lagaly, Gerhard, Beneke, Klaus, Weiss, Armin (1975) Magadiite and H-magadiite: I. Sodium magadiite and some of its derivatives. American Mineralogist, 60 (7-8) 642-649
Lagaly, Gerhard, Beneke, Klaus, Weiss, Armin (1975) Magadiite and H-magadiite: II. H-magadiite and its intercalation compounds. American Mineralogist, 60 (7-8) 650-658
Fletcher, Ross A. (1987) Synthesis of Kenyaite and Magadiite in the Presence of Various Anions. Clays and Clay Minerals, 35 (4) 318-320 doi:10.1346/ccmn.1987.0350410
Horváth, László, Gault, Robert A. (1990) The Mineralogy of Mont Saint-Hilaire, Quebec. The Mineralogical Record, 21 (4) 281-359
Scholzen, G., Beneke, K., Lagaly, G. (1991) Diversity of Magadiite. Zeitschrift fĂŒr anorganische und allgemeine Chemie, 597 (1). 183-196 doi:10.1002/zaac.19915970121
KOSUGE, Katsunori, YAMAZAKI, Atsushi, TSUNASHIMA, Atsumu, OTSUKA, Ryohei (1992) Hydrothermal Synthesis of Magadiite and Kenyaite. Journal of the Ceramic Society of Japan, 100 (1159) 326-331 doi:10.2109/jcersj.100.326
Almond, Graham G., Harris, Robin K., Franklin, Kevin R. (1997) A structural consideration of kanemite, octosilicate, magadiite and kenyaite. Journal of Materials Chemistry, 7. 681-687 doi:10.1039/a606856a
HorvĂĄth, LĂĄszlĂł, Gault, Robert A., Tarassoff, Peter, Pfenninger-HorvĂĄth, Elsa (1998) Mineralogy of the Saint-Amable Sill, Varennes and Saint-Amable, Quebec. The Mineralogical Record, 29 (2) 83-118
Eypert-Blaison, C., Villiéras, F., Michot, L. J ., Pelletier, M., Humbert, B., Ghanbaja, J ., Yvon, J . (2002) Surface heterogeneity of kanemite, magadiite and kenyaite: a high-resolution gas adsorption study. Clay Minerals, 37 (3) 531-542 doi:10.1180/0009855023730056
Wang, Yuh-Ruey, Wang, Sea-Fue, Chang, Li-Chung (2006) Hydrothermal synthesis of magadiite. Applied Clay Science, 33. 73-77 doi:10.1016/j.clay.2006.02.001
Marler, Bernd, Krysiak, YaƟar, Grosskreuz, Isabel, Gies, Hermann, Kolb, Ute (2022) The crystal structure of mineral magadiite, Na2Si14O28(OH)2∙8H2O. American Mineralogist, 107 (11) 2101-2110 doi:10.2138/am-2022-8156
(2023) Magadiite. Handbook of Mineralogy. Mineralogical Society of America

Localities for MagadiiteHide

Showing 15 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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Locality ListHide

- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Bolivia
 
  • PotosĂ­
    • Nor LĂ­pez Province
      • San Juan
Abdelouas et al. (1995)
Canada
 
  • QuĂ©bec
    • MontĂ©rĂ©gie
      • La VallĂ©e-du-Richelieu RCM
        • Mont Saint-Hilaire
Grice (1989) +1 other reference
      • Lajemmerais RCM
        • Varennes & St-Amable
HorvĂĄth et al. (1998)
HorvĂĄth et al. (1998)
Chad
 
Fletcher (1987)
Kenya
 
  • Baringo County
PĂ©rinet et al. (1982)
  • Kajiado County
New data on minerals. M.: 2003. Volume ... +3 other references
Namibia
 
  • Khomas Region
    • Windhoek Rural
      • Aris
 ... +1 other reference
Niger
 
  • Diffa
    • N'guigmi Department
Sebag et al. (2001)
Russia
 
  • Orenburg Oblast
    • Kvarkensky District
webmineral.ru (n.d.) +1 other reference
Sudan
 
  • North Darfur
    • Meidob Hills
Mees et al. (1991)
USA
 
  • California
    • Inyo County
Bricker (1969) +2 other references
    • Trinity County
      • Klamath Mountains
        • Trinity Mountains
          • Halls Gulch Mining District
            • Wildcat Peak
Lukasz Kruszewski specimen. +7 other references
  • Oregon
    • Harney County
Matthews (1992)
    • Lake County
Rooney et al. (1969)
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