Indialite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Indialite
Flag of India
Formula:
Mg2Al3(AlSi5O18)
Colour:
Colourless (thin section).
Lustre:
Vitreous
Hardness:
7 - 7½
Specific Gravity:
2.512
Crystal System:
Hexagonal
Member of:
Name:
Named by A. Miyashiro and T. Iiyama in 1954 after the country of India, where the type locality is located.
Type Locality:
Dimorph of:
The Mg analogue of ferroindialite.
The hexagonal high-temperature dimorph of cordierite (orthorhombic-pseudohexagonal).
Note: the formula has also been expressed as Al2SiMg2[Al2Si4]O18 (Pezzotta, 2005), and the mineral has been assigned to the beryl group.
Material at the type locality was anthropogenic (no longer treated this way, though) since it was formed as the result of fusion and recrystallization of rocks above burning coal seams. It was subsequently found in nature in hornfels, and rapidly quenched volcanic rocks.
The hexagonal high-temperature dimorph of cordierite (orthorhombic-pseudohexagonal).
Note: the formula has also been expressed as Al2SiMg2[Al2Si4]O18 (Pezzotta, 2005), and the mineral has been assigned to the beryl group.
Material at the type locality was anthropogenic (no longer treated this way, though) since it was formed as the result of fusion and recrystallization of rocks above burning coal seams. It was subsequently found in nature in hornfels, and rapidly quenched volcanic rocks.
Unique Identifiers
Mindat ID:
2026
Long-form identifier:
mindat:1:1:2026:4
Similar Names
IMA Classification of Indialite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mg2Al3(Si5AlO18)
Classification of Indialite
9.CJ.05
9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si6O18]12- 6-membered single rings (sechser-Einfachringe), without insular complex anions
9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si6O18]12- 6-membered single rings (sechser-Einfachringe), without insular complex anions
61.1.1.3
61 : CYCLOSILICATES Six-Membered Rings
1 : Six-Membered Rings with [Si6O18] rings; possible (OH) and Al substitution
61 : CYCLOSILICATES Six-Membered Rings
1 : Six-Membered Rings with [Si6O18] rings; possible (OH) and Al substitution
16.19.1
16 : Silicates Containing Aluminum and other Metals
19 : Aluminosilicates of Fe and Mg
16 : Silicates Containing Aluminum and other Metals
19 : Aluminosilicates of Fe and Mg
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 |
|---|---|---|
| Ind | 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 Indialite
Vitreous
Transparency:
Transparent
Colour:
Colourless (thin section).
Hardness:
7 - 7½ on Mohs scale
Density:
2.512 g/cm3 (Measured) 2.59 g/cm3 (Calculated)
Comment:
Measured values on artificial material.
Optical Data of Indialite
Type:
Uniaxial (-)
RI values:
nω = 1.539 nε = 1.534
Max. Birefringence:
δ = 0.005
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:
None to Very Low
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 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.
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.
Chemistry of Indialite
Mindat Formula:
Mg2Al3(AlSi5O18)
Element Weights:
Elements listed:
Common Impurities:
Fe,Mn,Na
Crystallography of Indialite
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P6/mcc
Cell Parameters:
a = 9.8 Å, c = 9.345 Å
Ratio:
a:c = 1 : 0.954
Unit Cell V:
777.25 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Small hexagonal grains and clusters of spiral-shaped grains, some exhibiting tentacles or multiple terminations.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
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) |
|---|---|---|---|---|---|---|---|
| 0001448 | Indialite | Daniels P (1992) Structural effects of the incorporation of large-radius alkalis in high cordierite American Mineralogist 77 407-411 |  | 1992 | synthetic | 0 | 293 |
| 0005136 | Indialite | Meagher E P, Gibbs G V (1977) The polymorphism of cordierite: II. The crystal structure of indialite The Canadian Mineralogist 15 43-49 | | 1977 | from a burning coal seam in the Bokaro coalfield, India | 0 | 293 |
| 0003187 | Indialite | Balassone G, Franco E, Mattia C A, Puliti R (2004) Indialite in xenolithic rocks from Somma-Vesuvius volcano (Southern Italy): Crystal chemistry and petrogenetic features American Mineralogist 89 1-6 | | 2004 | 0 | 293 | |
| 0007855 | Indialite | Schwartz K B, Leong D B, McConville R L (1994) Structural chemistry of synthetic cordierite: evidence for solid solutions and disordered compositional domains in Bi-flux-grown Mg-cordierites Physics and Chemistry of Minerals 20 563-574 | 1994 | 0 | 293 | ||
| 0007853 | Indialite | Schwartz K B, Leong D B, McConville R L (1994) Structural chemistry of synthetic cordierite: evidence for solid solutions and disordered compositional domains in Bi-flux-grown Mg-cordierites Physics and Chemistry of Minerals 20 563-574 | 1994 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.48 Å | (100) |
| 3.027 Å | (85) |
| 3.138 Å | (65) |
| 3.379 Å | (55) |
| 4.094 Å | (50) |
| 4.89 Å | (30) |
| 1.6882 Å | (30) |
Comments:
Obtained on artificial material.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 2: Planetesimal differentiation and alteration | 4.566-4.550 |
| 6 : Secondary asteroid phases | 4.566-4.560 |
| Stage 7: Great Oxidation Event | <2.4 |
| 45b : [Other oxidized fumarolic minerals] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 50 : Coal and/or oil shale minerals | <0.36 |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) |
Geological Setting:
Polymetamorphosed pelitic rock (Japan); volcanic eruptive matter (Bellerberg volcano).
Type Occurrence of Indialite
Geological Setting of Type Material:
Burning coal seam underlying sedimentary rocks
Associated Minerals at Type Locality:
Other Language Names for Indialite
Relationship of Indialite to other Species
Member of:
Other Members of Cordierite Group:
| Cordierite | Mg2Al4Si5O18 | Orth. mmm(2/m2/m2/m) : Cccm |
| Ferroindialite | (Fe2+,Mg)2Al4Si5O18 | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Sachanbińskiite | NaMn4(Al5Be)(AlSi5O18)2 · 2H2O | Orth. mmm(2/m2/m2/m) : Cccm |
| Sekaninaite | Fe2+2Al4Si5O18 | Orth. mmm(2/m2/m2/m) : Cccm |
Common Associates
Associations Based on Photo Data:
| 5 photos of Indialite associated with Pseudobrookite | Fe3+2Ti4+O5 |
| 2 photos of Indialite associated with Chalcanthite | CuSO4 · 5H2O |
| 2 photos of Indialite associated with Tridymite | SiO2 |
| 2 photos of Indialite associated with Tenorite | CuO |
| 1 photo of Indialite associated with Euchlorine | KNaCu3(SO4)3O |
| 1 photo of Indialite associated with Cuprite | Cu2O |
| 1 photo of Indialite associated with Hematite | Fe2O3 |
| 1 photo of Indialite associated with Native Copper | Cu |
| 1 photo of Indialite associated with Cordierite | Mg2Al4Si5O18 |
| 1 photo of Indialite associated with Paramelaconite | Cu+2Cu2+2O3 |
Related Minerals - Strunz-mindat Grouping
| 9.CJ. | Zolotarevite | Na5Zr[Si6O15(OH)3] · 3H2O |
| 9.CJ. | 'Avdeevite' | NaAl4(Be5Li)(Si6O18)2(H2O)1-2 |
| 9.CJ. | 'Beryllocordierite-Na' | NaMg4(Al5Be)(AlSi5O18)2 · 2H2O |
| 9.CJ. | Sachanbińskiite | NaMn4(Al5Be)(AlSi5O18)2 · 2H2O |
| 9.CJ. | Nakkaalaaqite | K2[Na3Ca]LiCa2Ti2Be4Si12O38 |
| 9.CJ.05 | Johnkoivulaite-(Cs) | Cs[Be2B]Mg2Si6O18 |
| 9.CJ.05 | Beryl | Be3Al2(Si6O18) |
| 9.CJ.05 | Bazzite | Be3Sc2(Si6O18) |
| 9.CJ.05 | Ferroindialite | (Fe2+,Mg)2Al4Si5O18 |
| 9.CJ.05 va | 'Vorobyevite' | Be3Al2(Si6O18) |
| 9.CJ.05 | Stoppaniite | Be3Fe3+2(Si6O18) · H2O |
| 9.CJ.10 | Sekaninaite | Fe2+2Al4Si5O18 |
| 9.CJ.10 | Cordierite | Mg2Al4Si5O18 |
| 9.CJ.15a | Zirsinalite | Na6(Ca,Mn2+,Fe2+)Zr(Si6O18) |
| 9.CJ.15a | Kapustinite | Na6ZrSi6O16(OH)2 |
| 9.CJ.15a | Townendite | Na8ZrSi6O18 |
| 9.CJ.15a | Combeite | Na4.5Ca3.5Si6O17.5(OH)0.5 |
| 9.CJ.15a | Kazakovite | Na6Mn2+Ti(Si6O18) |
| 9.CJ.15a | Tisinalite | Na3H3(Mn,Ca,Fe)TiSi6(O,OH)18 · 2H2O |
| 9.CJ.15a | Lovozerite | Na2Ca(Zr,Ti)(Si6O12)[(OH)4O2] · H2O |
| 9.CJ.15a | Litvinskite | Na2(◻,Na,Mn)ZrSi6O12(OH,O)6 |
| 9.CJ.15c | Koashvite | Na6(Ca,Mn)(Ti,Fe)Si6O18 · H2O |
| 9.CJ.15b | Imandrite | Na12Ca3Fe3+2(Si6O18)2 |
| 9.CJ.25 | Baratovite | KCa7(Ti,Zr)2Li3Si12O36F2 |
| 9.CJ.25 | Aleksandrovite | KCa7Sn2Li3Si12O36F2 |
| 9.CJ.25 | Katayamalite | KLi3Ca7Ti2(SiO3)12(OH)2 |
| 9.CJ.30 | Dioptase | CuSiO3 · H2O |
| 9.CJ.35 | Kostylevite | K2Zr(Si3O9) · H2O |
| 9.CJ.40 | Petarasite | Na5Zr2(Si6O18)(Cl,OH) · 2H2O |
| 9.CJ.45 | Gerenite-(Y) | (Ca,Na)2(Y,REE)3Si6O18 · 2H2O |
| 9.CJ.50 | Odintsovite | K2Na4Ca3Ti2Be4Si12O38 |
| 9.CJ.55 | Mathewrogersite | Pb7FeAl3GeSi12O36(OH,H2O)6 |
| 9.CJ.60 | Pezzottaite-(Cs) | Cs(Be2Li)Al2(Si6O18) |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Industrial Uses:
None.
Internet Links for Indialite
mindat.org URL:
https://www.mindat.org/min-2026.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 Indialite
Reference List:
Venkatesh, V. (1952) Development and growth of cordierite in para-lavas. American Mineralogist, 37 (9-10) 831-848
Miyashiro, A., Iiyama, T., Miyashiro, T., Yamasaki, M. (1955) The polymorphism of cordierite and indialite. American Journal of Science, 253 (4) 185-208 doi:10.2475/ajs.253.4.185
Miyashiro, A. (1957) Cordierite-indialite relations. American Journal of Science, 255 (1) 43-62 doi:10.2475/ajs.255.1.43
Kitamura, Masao, Hiroi, Yoshikuni (1982) Indialite from Unazuki Pelitic Schist, Japan, and its transition texture to cordierite. Contributions to Mineralogy and Petrology, 80 (2) 110-116 doi:10.1007/bf00374888
Daniels, P. (1990) What is the true space group of high-cordierite? Zeitschrift für Kristallographie, 190 (3-4). 271-276 doi:10.1524/zkri.1990.190.3-4.271
Daniels, Peter (1992) Structural effects of the incorporation of large radius alkalis in high cordierite. American Mineralogist, 77 (3-4) 407-411
Localities for Indialite
Showing 38 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.
Austria | |
| U. Kolitsch et al. (2009) |
Czech Republic | |
| Žáček et al. (1995) |
| V. Zacek |
| Matýsek et al. (2022) |
Germany | |
| in: Stracher +1 other reference |
| Igor Pekov +2 other references |
| rruff.geo.arizona.edu (2006) |
| Witzke (1996) |
| Witzke et al. (1998) |
India | |
| Kumar +1 other reference |
| Current Science (1954) |
| Miyashiro (1954) |
| Subramaniam (1955) |
Italy | |
| Balassone et al. (2004) |
| Renzulli +4 other references |
| Stoppa et al. (2014) |
Japan | |
| Rakovan et al. (2006) |
| Rocks & Minerals 81:284-292 +1 other reference |
| Yamada (2004) | |
| Kitamura et al. (1982) |
Mongolia | |
| Savina et al. (2020) +1 other reference |
| Peretyazhko et al. (2017) +1 other reference |
| Peretyazhko et al. (2018) |
| Peretyazhko et al. (2018) | |
| Peretyazhko et al. (2018) | |
| Peretyazhko et al. (2017) | |
Poland | |
| Łukasz Kruszewski PXRD data |
| Ł. Kruszewski EPMA/PXRD data +1 other reference |
| Ciesielczuk et al. (2014) |
| Ł. Kruszewski PXRD data (W. Sierny specimen) |
| Ł. Kruszewski PXRD and EPMA data |
Russia | |
| Cesnokov et al. (1998) |
| Shchipalkina et al. (2020) |
| Shchipalkina et al. (2020) |
| Pekov et al. (2018) +1 other reference | |
USA | |
| Castor et al. (2004) |
| R. Stach and J. Harkensen (1974) |
| Gunnar Färber - Mineralienliste 3-2017. |
Quick NavTopAbout IndialiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Nickenicher Weinberg, Nickenich, Pellenz, Mayen-Koblenz, Rhineland-Palatinate, Germany