Log InRegister
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreOur ScienceMindat Newsletter [Free Download]Contact Us
Donate to MindatSponsor a PageCorporate SponsorshipSponsored Pages
Learning CenterWhat Is a Mineral?The Most Common Minerals on EarthInformation for EducatorsMindat ArticlesMindat Newsletter [Free Download]The ElementsThe Mineral Quiz
Search FormMinerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDMinerals by CountryAlphabetical Mineral IndexAlphabetical Locality SearchMineral Association SearchList of CountriesLocalities Near MePhoto SearchSearch ArticlesSearch GlossaryThe Rock H. Currier Digital LibraryMore Search Options
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
MineralsPetrologyFossilsMeteoritesGeologic Time
Mining CompaniesStatisticsMineral MuseumsClubs & OrganizationsMineral Shows & EventsDevice SettingsTime Machine
Read DiscussionsIdentification Request
Photo SearchPhoto GalleriesSearch by ColourPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Yagiite

A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
05676800017271927646834.jpg
Kenzo Yagi
Formula:
Na◻2Mg2Al3[Al2Si10O30]
IMA formula given as: Na◻2Mg2(AlMg2)[Si12O30], which does indeed charge-balance.

Gagné & Hawthorne (2016) report an alternative and also charge-balanced formula, which eliminates Mg from the T2 site: Na◻2Mg2Al3[Al2Si10O30].

The actual formula based on the reported oxide%, normalized to T1+T2+A = 17, corresponds to: (Na1.19K0.30◻1.51)(Mg1.55Fe2+0.20Fe3+0.13Ti0.10Ca0.02)(Al1.96Mg1.04)[Al1.77Si10.23O30], which approximately reduces to the charge-balanced formula: Na(◻Na)Mg2(Al2Mg)[Al2Si10O30]. This formula shows a T2 site mix of Al and Mg intermediate between the IMA and Gagné & Hawthorne (2016) formulas, but requires an extra 1+ cation to charge balance (hence the B site as (◻Na) instead of ◻2 as per the other formulas).

Although not entirely consistent with the natural composition, the formula of Gagné & Hawthorne 2016 is presented as our "mindat" formula for this mineral.

Colour:
Colourless
Hardness:
5 - 6
Specific Gravity:
2.70 (Calculated)
Crystal System:
Hexagonal
Member of:
Osumilite Group
Name:
Named by Theodore E. Bunch and Louis H. Fuchs in 1969 in honor of Kenzo Yagi (15 September 1915, Nagano City, Nagano Prefecture, Japan - 18 July 2008), Professor of Geology, Hokkaido University, Sapporo, Japan for his contributions to mineralogy and petrology.
Na-dominant member of the osumilite group.


Hide all sections | Show all sections

Unique IdentifiersHide

Mindat ID:
4350
Long-form identifier:
mindat:1:1:4350:8

Similar NamesHide

AugiteA valid IMA mineral species - grandfathered(CaxMgyFez)(Mgy1Fez1)Si2O6
Uigite

IMA Classification of YagiiteHide

IMA status:
Approved
IMA Formula:
NaMg2(AlMg2Si12)O30
Approval year:
1968
First published:
1969
Type description reference:
Bunch, Theodore E., Fuchs, Louis H. (1969) Yagiite, a new sodium-magnesium analogue of osumilite. American Mineralogist, 54 (1-2) 14-18

Classification of YagiiteHide

Strunz-mindat (2026):
9.CM.05

9 : SILICATES (Germanates)
C : Cyclosilicates
M : [Si6O18]12- 6-membered double rings (sechser-Doppelringe)
Dana 8th ed.:
63.2.1a.10

63 : CYCLOSILICATES Condensed Rings
2 : Condensed Rings (Milarite - Osumilite group)
Hey's CIM Ref.:
16.8.5

16 : Silicates Containing Aluminum and other Metals
8 : Aluminosilicates of Mg and alkalis

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
YagIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of YagiiteHide

Transparency:
Translucent
Colour:
Colourless
Comment:
Can be very light blue in thin section
Hardness:
5 - 6 on Mohs scale
Density:
2.70 g/cm3 (Calculated)

Optical Data of YagiiteHide

Type:
Uniaxial (+)
RI values:
nω = 1.536(2) nε = 1.544(2)
Max. Birefringence:
δ = 0.008
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.

Surface Relief:
None to Very Low
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.
Pleochroism:
Weak
Comments:
O = very light blue; E = colorless

Chemistry of YagiiteHide

Mindat Formula:
Na◻2Mg2Al3[Al2Si10O30]

IMA formula given as: Na◻2Mg2(AlMg2)[Si12O30], which does indeed charge-balance.

Gagné & Hawthorne (2016) report an alternative and also charge-balanced formula, which eliminates Mg from the T2 site: Na◻2Mg2Al3[Al2Si10O30].

The actual formula based on the reported oxide%, normalized to T1+T2+A = 17, corresponds to: (Na1.19K0.30◻1.51)(Mg1.55Fe2+0.20Fe3+0.13Ti0.10Ca0.02)(Al1.96Mg1.04)[Al1.77Si10.23O30], which approximately reduces to the charge-balanced formula: Na(◻Na)Mg2(Al2Mg)[Al2Si10O30]. This formula shows a T2 site mix of Al and Mg intermediate between the IMA and Gagné & Hawthorne (2016) formulas, but requires an extra 1+ cation to charge balance (hence the B site as (◻Na) instead of ◻2 as per the other formulas).

Although not entirely consistent with the natural composition, the formula of Gagné & Hawthorne 2016 is presented as our "mindat" formula for this mineral.

Element Weights:
Element% weight
O49.619 %
Si29.034 %
Al13.946 %
Mg5.025 %
Na2.377 %

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

Crystallography of YagiiteHide

Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P6/mcc
Setting:
P6/mcc
Cell Parameters:
a = 10.09(1) Å, c = 14.29(3) Å
Ratio:
a:c = 1 : 1.416
Unit Cell V:
1,259.93 ų (Calculated from Unit Cell)
Z:
2

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
3.228 Å(100)
5.059 Å(65)
3.726 Å(50)
2.765 Å(50)
2.090 Å(40)
7.12 Å(30)
2.003 Å(30)

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 2: Planetesimal differentiation and alteration4.566-4.550
5 : Primary asteroid phases4.566–4.560

Type Occurrence of YagiiteHide

Type Locality:
ⓘ Colomera meteorite, Colomera, Granada, Andalusia, Spain
General Appearance of Type Material:
Interstitial to small equant grains.
Geological Setting of Type Material:
Silicate inclusions in an iron meteorite.
Associated Minerals at Type Locality:
Diopside'Nickel-iron'PlagioclaseTridymiteWhitlockite
Reference:
Bunch, Theodore E., Fuchs, Louis H. (1969) Yagiite, a new sodium-magnesium analogue of osumilite. American Mineralogist, 54 (1-2) 14-18

Synonyms of YagiiteHide

Other Language Names for YagiiteHide

Relationship of Yagiite to other SpeciesHide

Member of:
Osumilite Group
Other Members of Osumilite Group:
Agakhanovite-(Y)K◻2(YCa)Be3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
AlmaruditeK◻2Mn2+2(Be2Al)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mmm
AluminosugiliteKNa2Al2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
ArmeniteBa(H2O)2Ca2Al3[Al3Si9O30]Orth. mmm(2/m2/m2/m) : Pnna
BerezanskiteK◻2Ti2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
BrannockiteK◻2Sn2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
ChayesiteK◻2Mg2(Mg2Fe3+)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
DarapiositeKNa2Mn2(Zn2Li)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
DusmatoviteK(K◻)Mn2+2Zn3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
EifeliteKNa2(MgNa)Mg3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
FriedrichbeckeiteK(◻Na)Mg2(Be2Mg)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
KlöchiteK◻2(Fe2+Fe3+)Zn3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P63/mmc
LaurentthomasiteK◻2Mg2(Be2Al)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
MerrihueiteK(◻Na)Fe2+2Fe2+3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
MilariteK(◻H2O)Ca2(Be2Al)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
OftedaliteK◻2(ScCa)Be3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
OsumiliteK◻2Fe2+2Al3[Al2Si10O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
Osumilite-(Mg)K◻2Mg2Al3[Al2Si10O30] Hex. 6/mmm(6/m2/m2/m) : P6/mcc
PlechoviteCa2[K(H2O)]KBe3Si12O30Hex. 6/mmm(6/m2/m2/m) : P6/mcc
PoudretteiteK◻2Na2B3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
RoedderiteK(◻Na)Mg2Mg3[Si12O30]Hex. 6m2 : P62c
ShibkoviteK(◻K)Ca2Zn3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
SogdianiteK◻2Zr2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
SugiliteKNa2Fe3+2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
Trattnerite◻(◻)2Fe3+2Mg3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
'UM1990-73-SiO:KMnNaZn'K(KNa0.5◻0.5)(Mn1.5Na0.5)Zn3[Si12O30]Hex.
'Unnamed (Mn3+-dominant analog of Sugilite)'KNa2Mn3+2Li3[Si12O30]

Related Minerals - Strunz-mindat GroupingHide

9.CM.AluminosugiliteKNa2Al2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.Agakhanovite-(Y)K◻2(YCa)Be3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.PlechoviteCa2[K(H2O)]KBe3Si12O30Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05FriedrichbeckeiteK(◻Na)Mg2(Be2Mg)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05LaurentthomasiteK◻2Mg2(Be2Al)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05'UM1990-73-SiO:KMnNaZn'K(KNa0.5◻0.5)(Mn1.5Na0.5)Zn3[Si12O30]Hex.
9.CM.05EifeliteKNa2(MgNa)Mg3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05AlmaruditeK◻2Mn2+2(Be2Al)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mmm
9.CM.05ArmeniteBa(H2O)2Ca2Al3[Al3Si9O30]Orth. mmm(2/m2/m2/m) : Pnna
9.CM.05MerrihueiteK(◻Na)Fe2+2Fe2+3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05OftedaliteK◻2(ScCa)Be3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05RoedderiteK(◻Na)Mg2Mg3[Si12O30]Hex. 6m2 : P62c
9.CM.05ShibkoviteK(◻K)Ca2Zn3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05SogdianiteK◻2Zr2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05MilariteK(◻H2O)Ca2(Be2Al)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05BerezanskiteK◻2Ti2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05PoudretteiteK◻2Na2B3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05DarapiositeKNa2Mn2(Zn2Li)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05ChayesiteK◻2Mg2(Mg2Fe3+)[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05Osumilite-(Mg)K◻2Mg2Al3[Al2Si10O30] Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05OsumiliteK◻2Fe2+2Al3[Al2Si10O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05SugiliteKNa2Fe3+2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05Trattnerite◻(◻)2Fe3+2Mg3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05BrannockiteK◻2Sn2Li3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.05KlöchiteK◻2(Fe2+Fe3+)Zn3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P63/mmc
9.CM.05DusmatoviteK(K◻)Mn2+2Zn3[Si12O30]Hex. 6/mmm(6/m2/m2/m) : P6/mcc
9.CM.10FaizieviteK2Na(Ca6Na)Ti4Li6[Si6O18]2[Si12O30]F2Tric. 1 : P1

Other InformationHide

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 YagiiteHide

References for YagiiteHide

Localities for YagiiteHide

Showing 3 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.
Hide all sections | Show all sections

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.
Japan
 
  • Aichi Prefecture
    • Tahara City
Miura et al. (1994)
Mexico
 
  • Zacatecas
    • Sombrerete Municipality
Ruzicka et al. (2006)
Spain (TL)
 
  • Andalusia
    • Granada
      • Colomera
[AM 54 (1969) +1 other reference
Quick NavTopUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsStrunz-MindatOther InformationInternet Links References Localities Locality List
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: November 1, 2026 01:31:33 Page updated: September 8, 2026 04:35:49
Go to top of page