Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Kyanite

This page is currently not sponsored. Click here to sponsor this page.
Formula:
Al2(SiO4)O
System:
Triclinic
Colour:
Blue, white, light gray, ...
Lustre:
Vitreous, Sub-Vitreous, Greasy, Pearly
Hardness:
5½ - 7
Name:
Named in 1789 by Abraham Gottlieb Werner from the Greek word "kyanos", meaning "blue," the common color of the species. The French spelling, "Cyanite", was commonly used by mineralogists through much of the 19th and early 20th centuries.
Polymorph of:
Common metamorphic silicate mineral.
The generally blueish colour is caused by Fe(II)-Fe(III) charge transfer (Faye and Nickel, 1969).


Visit gemdat.org for gemological information about Kyanite.

Classification of Kyanite

Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
9.AF.15

9 : SILICATES (Germanates)
A : Nesosilicates
F : Nesosilicates with additional anions; cations in [4], [5] and/or only [6] coordination
52.2.2c.1

52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
2 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [4] and >[4] coordination
15.2

15 : Silicates of Aluminum
mindat.org URL:
http://www.mindat.org/min-2303.html
Please feel free to link to this page.

Occurrences of Kyanite

Geological Setting:
Metamorphic rocks of moderately high pressure regional metamorphism.

Physical Properties of Kyanite

Vitreous, Sub-Vitreous, Greasy, Pearly
Diaphaneity (Transparency):
Transparent, Translucent
Comment:
Somewhat pearly on {100} || to the perfect cleavage
Colour:
Blue, white, light gray, green, rarely yellow, orange, pink
Streak:
Colorless
Hardness (Mohs):
5½ - 7
Comment:
5.5 parallel to [001], 7 parallel to [100]
Tenacity:
Brittle
Cleavage:
Perfect
Perfect on (100), good on (010)
Parting:
On (001)
Fracture:
Splintery
Density:
3.53 - 3.67 g/cm3 (Measured)    3.67 g/cm3 (Calculated)

Crystallography of Kyanite

Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Space Group Setting:
P1
Cell Parameters:
a = 7.1262(12) Å, b = 7.8520(10) Å, c = 5.5724(10) Å
α = 89.99(2)°, β = 101.11(2)°, γ = 106.03(1)°
Ratio:
a:b:c = 0.908 : 1 : 0.71
Z:
4
Morphology:
Crystals bladed or tabular.
Twinning:
Lamellar on (100), common
Comment:
Non-standard setting.

Crystallographic forms of Kyanite

Crystal Atlas:
Image Loading
Click on an icon to view
Kyanite no.6 - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by www.smorf.nl.

Toggle
Edge Lines | Miller Indicies | Axes

Transparency
Opaque | Translucent | Transparent

View
Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation
X-Ray Powder Diffraction:
Image Loading

Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.
X-Ray Powder Diffraction Data:
d-spacingIntensity
3.35 (100)
3.18 (20)
2.70 (40)
2.51 (50)
2.35 (40)
2.16 (20)
1.960 (50)
1.929 (80)
Comments:
ICDD 11-46

Optical Data of Kyanite

Type:
Biaxial (-)
RI values:
nα = 1.712 - 1.718 nβ = 1.720 - 1.725 nγ = 1.727 - 1.734
2V:
Measured: 82° to 83°, Calculated: 84°
Birefringence:
0.015
Max Birefringence:
δ = 0.015 - 0.016
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
High
Dispersion:
r > v weak
Optical Extinction:
Inclined. Z>Y>X; X perpendicular to {100}, Z' ^ c = 30° on {100}, Z' ^ c = 7° on {010}.
Pleochroism:
Weak
Comments:
X= colorless
Y= violet-blue
Z= cobalt blue

Chemical Properties of Kyanite

Formula:
Al2(SiO4)O
Essential elements:
All elements listed in formula:

Relationship of Kyanite to other Species

9.AF.05SillimaniteAl2(SiO4)O
9.AF.10AndalusiteAl2(SiO4)O
9.AF.10KanonaiteMn3+Al(SiO4)O
9.AF.20MulliteAl4+2xSi2-2xO10-x
9.AF.20Krieselite(Al,Ga)2(GeO4)(OH)2
9.AF.23BoromulliteAl9BSi2O19
9.AF.25YoderiteMg(Al,Fe3+)3(SiO4)2O(OH)
9.AF.30MagnesiostauroliteMg(Mg,Li)3(Al,Mg)18Si8O44(OH)4
9.AF.30StauroliteFe22+Al9Si4O23(OH)
9.AF.30ZincostauroliteZn2Al9Si4O23(OH)
9.AF.35TopazAl2(SiO4)(F,OH)2
9.AF.40NorbergiteMg3(SiO4)(F,OH)2
9.AF.45AlleghanyiteMn52+(SiO4)2(OH)2
9.AF.45Chondrodite(Mg,Fe2+)5(SiO4)2(F,OH)2
9.AF.45ReinhardbraunsiteCa5(SiO4)2(OH,F)2
9.AF.45KumtyubeiteCa5(SiO4)2F2
9.AF.45HydroxylchondroditeMg5(SiO4)2(OH)2
9.AF.50Humite(Mg,Fe2+)7(SiO4)3(F,OH)2
9.AF.50Manganhumite(Mn2+,Mg)7(SiO4)3(OH)2
9.AF.50Unnamed (Ca-analogue of Humite)Ca7(SiO4)4F2
9.AF.55ClinohumiteMg9(SiO4)4F2
9.AF.55SonoliteMn92+(SiO4)4(OH,F)2
9.AF.55HydroxylclinohumiteMg9(SiO4)4(OH)2
9.AF.60LeucophoeniciteMn72+(SiO4)3(OH)2
9.AF.65Ribbeite(Mn2+,Mg)5(SiO4)2(OH)2
9.AF.70JerrygibbsiteMn92+(SiO4)4(OH)2
9.AF.75FranciscaniteMn62+(V5+,☐)2(SiO4)2(O,OH)6
9.AF.75ÖrebroiteMn32+(Sb5+,Fe3+)(SiO4)(O,OH)3
9.AF.75WeliniteMn62+(W6+,Mg)2(SiO4)2(O,OH)6
9.AF.80EllenbergeriteMg6(Mg,Ti,Zr,◻)2(Al,Mg)6Si8O28(OH)10
9.AF.85Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
9.AF.85MagnesiochloritoidMgAl2(SiO4)O(OH)2
9.AF.85Ottrélite(Mn2+,Fe2+,Mg)Al2(SiO4)O(OH)2
9.AF.90PoldervaartiteCaCa[SiO3(OH)](OH)
9.AF.90OlmiiteCaMn2+[SiO3(OH)](OH)
15.1AndalusiteAl2(SiO4)O
15.3SillimaniteAl2(SiO4)O
15.4MulliteAl4+2xSi2-2xO10-x
15.5PyrophylliteAl2(Si4O10)(OH)2
15.6DickiteAl2(Si2O5)(OH)4
15.7NacriteAl2(Si2O5)(OH)4
15.8KaoliniteAl2(Si2O5)(OH)4
15.9Metahalloysite
15.10HalloysiteAl2(Si2O5)(OH)4
15.11Allophane(Al2O3)(SiO2)1.3-2 · 2.5-3H2O

Other Names for Kyanite

Name in Other Languages:

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:
Ceramics

References for Kyanite

Reference List:
Klaproth, M.H. (1810): Chemische Untersuchung des Kyanits, Beiträge zur chemischen Kenntniss der Mineralkörper, Fünfter Band, Rottmann Berlin, 6-11

Clark, S.P., E.C. Robertson & F. Birch (1957), Experimental determination of kyanite-sillimanite equilibrium relations at high temperatures and pressure: American Journal of Science: 255: 628-640.

Pearson, G.R. and Shaw, D.M. (1960) Trace elements in kyanite, sillimanite and andalusite. American Mineralogist: 45: 808-817.

Burnham, C.W. (1963b) Refinement of the crystal structure of kyanite. Zeitschrift für Kristallographie: 118: 337-360.

Sgarlata, F. (1965) La struttura della cianite. Periodico di Mineralogia – Roma, 241-256.

Hafner, S.S. and Raymond, M. (1967) Nuclear quadrupole coupling tensors of Al27 in kyanite. American Mineralogist: 52: 1632-1642.

Chinner, G.A., J.W. Smith & C.R. Knowles (1969): Transition metal contents of Al2SiO5 polymorphs: American Journal of Science: 267A: 96-113.

G. H. Faye and E. H. Nickel (1969): On the origin of colour and pleochroism of kyanite. Can. Mineral. 10, 35-46.

Winter, J.K. and Ghose, S. (1979) Thermal expansion and high-temperature crystal chemistry of the Al2SiO5 polymorphs. American Mineralogist: 64: 573-586.

Kerrick, D.M. (1990) Metamorphic reactions. In D.M. Kerrick, Ed., The Al2SiO5 polymorphs. 22, 223-253. Reviews in Mineralogy. Mineralogical Society of America, Chantilly, Virginia.

Kerrick, D.M. (1990) The Al2SiO5 polymorphs, 22, 406 p. Reviews in Mineralogy, Mineralogical Society of America, Chantilly, Virginia.

Comodi, P., Zanazzi, P.F., Poli, S., and Schmidt, M.W. (1997) High pressure behavior of kyanite: decomposition of kyanite into stishovite and corundum. American Mineralogist: 82: 460-466.

Yang, H., Downs, R.T., Finger, L.W., Hazen, R.M., and Prewitt, C.T. (1997a) Compressibility and crystal structure of kyanite at high pressure. American Mineralogist: 82: 467-474.

Pan, Y. and Fleet, M.E. (1999) Kyanite in the Western Superior Province of Ontario: implications for Archean accretionary tectonics. Canadian Mineralogist: 37: 359-373.

Rao, M.N., Chaplot, S.L., Choudhury, N., Rao, K.R., Azuah, R.T., Montfrooji, W.T., and Bennington, S.M. (1999) Lattice dynamics and inelastic neutron scattering from sillimanite and kyanite Al2SiO5. Physical Review: B60: 12061.

Dahaoui, S., Ghermani, N.E., Ghose, S., and Howard, J.A.K. (2001) Electric field gradient tensors at the aluminum sites in the Al2SiO5 polymorphs from CCD high resolution X-ray diffraction data: comparison with 27 Al NMR results. American Mineralogist: 86: 159-164.

Iglesias, M., Schwarz, K., Blaha, P., and Baldomir, D. (2001) Electronic structure and electric field gradient calculations of Al2SiO5 polymorphs. Physics and Chemistry of Minerals: 28: 67-75.

Winkler, B., Hytha, M., Warren, M.C., Milman, V., Gale, J.D., and Schreuer, J. (2001) Calculation of the elastic constants of the Al2SiO5 olymorphs andalusite, sillimanite, and kyanite. Zeitschrift für Kristallographie: 216: 67-70.

Wieczorek, A.K. and Beran, A. (2002) Infrared spectroscopic characterization of OH defects in kyanite. 18th IMA General Meeting 1st to 6th September Edinburgh, Scotland (2002).

Bell, D., Rossman, G.R., Maldener J., Endisch, D., and Rauch, F. (2004) Hydroxide in kyanite: a quantitative determinationof the absolute amount and calibration of the IR spectrum. American Mineralogist: 89: 998-1003.

Friedrich, A., Kunz, M., Winkler, B., and Le Bihan T. (2004) High-pressure beahvior of sillimanite and kyanite: compressibility, decomposition and indications of a new high-pressure phase. Zeitschrift für Kristallographie: 219: 324-329.

Ohuchi, F.S., Ghose, S., Engelhard, M.H., and Baer, D.R. (2006) Chemical bonding and electronic structures of the Al2SiO5 polymorphs, andalusite, sillimanite, and kyanite: X-ray photoelectron- and electron energy loss spectroscopy studies. American Mineralogist: 91: 740-746.

Chadwick, K.M. & Rossman, G.R. (2009) Orange kyanite from Tanzania. Gems & Gemology 45, 146-147.

Manfred Wildner, Anton Beran, Friedrich Koller (2013): Spectroscopic characterisation and crystal field calculations of varicoloured kyanites from Loliondo, Tanzania. Mineral. Petrol. 107, 289-310.

Internet Links for Kyanite

Specimens:
The following Kyanite specimens are currently listed for sale on minfind.com.

Localities for Kyanite

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.
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2015, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: July 5, 2015 09:01:03 Page generated: July 2, 2015 09:53:05