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INVESTIGATIONS

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

Colour

Locality

Info

nx min

nx max

ny min

ny max

nz min

nz max

Spectrum

UVS

UVL

Reference

Kyanite

1.709

1.729

0.02

0.02

3.64

3.64

blue

Nepal

1.71ct

 

 

 

 

 

 

 

 

 

http://www.geminterest.com 2003

Kyanite

1.709

1.729

0.016

0.019

3.65

3.68

blue

Nepal

biaxial positive, 2.87 to 12.26 ct

1.709

1.712

1.716

1.719

1.726

1.729

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2012 Dez, p91-97

Kyanite

1.71

1.728

0.017

0.017

3.6

3.6

 

Nepal

biaxal POSITIVE (=rare)

1.710

1.711

 

 

1.727

1.728

 

weak yellowish green

very weak yellowish green

Gems & Gemology 2002 spring p 96

Kyanite

1.71

1.722

0.012

0.012

3.74

3.74

greenish blue

Madagascar

2.77ct, biaxial -

 

 

 

 

 

 

lines at 440, 450

 

 

GIA Gem Database  33835

Kyanite

1.71

1.73

0.02

0.02

3.68

3.68

intense blue

 

8.54ct

 

 

 

 

 

 

430 and 445 nm lines

 

 

Gems & Gemology 2007 Fall, p248

Kyanite

1.71

1.728

0.018

0.018

3.54

3.86

blue

Pakistan

2 stones of 0.85ct, biaxial -

 

 

 

 

 

 

 

 

 

The Journal of Gemmology 2016 Vol 35, No. 2, p103-104

Kyanite

1.711

1.728

0.016

0.016

3.68

3.68

light greenish blue, very dark blue, nearly colourless

Arusha region, Tanzania

transparent to semi transparent

1.711

1.712

 

 

1.727

1.728

680 line

very weak chalky green

moderate to very weak red

Gems & Gemology 2004 winter p341

Kyanite

1.711

1.739

0.018

0.018

3.69

3.69

green

Bahia, Brazil

 

 

 

 

 

 

 

bands 435nm and 445nm

 

 

Gems & Gemology 2001 winter p338

Kyanite

1.711

1.735

0.017

0.024

3.67

3.68

greenish blue, light blue

Brazil

2.42ct, 2.46ct, 30.68ct

 

 

 

 

 

 

 

 

 

http://www.geminterest.com 2003

Kyanite

1.712

1.728

0.015

0.015

3.67

3.67

greyish

 

 

 

 

 

 

 

 

 

 

 

The Journal of Gemmology 1988 Vol 21, N°2, p83-87

Kyanite

1.712

1.729

0.017

0.017

3.68

3.68

blue

Nepal

3.03ct

1.712

1.712

1.721

1.721

1.729

1.729

 

inert

inert

ACAM lab  4400

Kyanite

1.714

1.731

0.017

0.017

3.676

3.676

blue colour-changing (reddish)

East Africa

 

1.714

1.714

1.724

1.724

1.731

1.731

 

 

 

The Journal of Gemmology 1982 Vol18, N°3, p205-212

Kyanite

1.715

1.734

0.016

0.016

3.67

3.69

sapphire blue

Nepal

3.37ct to 12.2ct, high transparency

1.715

1.718

1.726

1.727

1.731

1.734

431nm , 444nm

 

 

The Australian Gemmologist 2004 Vol 22, N°1, p32-34

Kyanite

1.715

1.731

0.016

0.016

3.68

3.68

blue

 

2.5ct

 

 

 

 

 

 

 

 

 

ACAM lab

Kyanite

1.715

1.732

0.017

0.017

3.69

3.69

orange

 

0.85ct

1.715

1.715

1.724

1.724

1.732

1.732

 

inert

dark red

ACAM lab  2281

Kyanite

1.715

1.732

0.017

0.017

3.67

3.67

green

Odisha, India

9.58ct, biaxe +

 

 

 

 

 

 

 

inert

inert

http://www.spec4gem.info/index.php 2017

Kyanite-Cr

1.716

1.731

0.015

0.015

3.69

3.69

greenish-blue

 

 

 

 

 

 

 

 

670, 690, broad band 575nm

very weak green

weak to moderate red

Gems & Gemology 2007 fall p 256

Kyanite

1.716

1.734

0.018

0.018

3.7

3.7

orange

Loliondo, Tanzania

biaxial -

1.716

1.716

1.727

1.727

1.734

1.734

 

inert

inert

http://www.geminterest.com 2008

Kyanite

1.716

1.728

0.012

0.012

3.7

3.7

bluish green

Mwami, Mashonaland West Province, Zimbabwe

3.55ct, biaxial +

 

 

 

 

 

 

lines at 438, 451, 695nm

inert

inert

GIA Gem Database  35283

Kyanite

1.716

1.73

0.014

0.014

3.83

3.83

bluish green

Tanzania

15.81ct, biaxial -

 

 

 

 

 

 

lines at 440 , 450nm

 

 

GIA Gem Database  34993

Kyanite

1.716

1.73

0.014

0.014

3.67

3.67

medium light, moderately strong, slightly greenish blue

Umba area, Tanzania

0.19ct, 1.68ct, chelsea filter: red

 

 

 

 

 

 

2 dark lines in the deep red region with a red fluorescent line between them, cut-off at 430nm

chalky green-white

weak red

The Journal of Gemmology 2014 Vol 34, No 3, p198-200

Kyanite

1.718

1.735

0.016

0.017

3.69

3.73

orange

Loliondo, Tanzania

biaxe negative, chelsea inert

1.718

1.718

 

 

1.734

1.735

line at 550nm, band at 460-500nm

inert

inert

Gems & Gemology 2009 summer, p146-147

Kyanite

1.718

1.732

0.014

0.014

3.66

3.69

oranje-bruin

Loliondo, Tanzania

0.30 - 0.80 ct

 

 

 

 

 

 

line at 550nm

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2009 58/3-4/Dec, p77

Kyanite

1.718

1.73

0.012

0.012

3.68

3.68

blue

Dolpo, Karnali, Nepal

5.78ct, biaxial -

 

 

 

 

 

 

 

inert

inert

GIA Gem Database  34742

Kyanite

1.718

1.732

0.014

0.014

3.74

3.74

greenish blue

Brazil

6.10ct, biaxial -

 

 

 

 

 

 

 

inert

inert

GIA Gem Database  34274

Kyanite

1.718

1.73

0.012

0.012

3.75

3.75

yellowish green

Brazil

8.37ct, biaxial -

 

 

 

 

 

 

lines at 438, 451

inert

inert

GIA Gem Database  33854

Kyanite

1.718

1.734

0.016

0.016

3.67

3.69

light yellow-green

Brazil

with orange-brown garnet inclusions to 1mm

1.718

1.718

1.727

1.727

1.734

1.734

 

inert

inert

Gems & Gemology 2002 Summer, p178-179

Kyanite

1.719

1.731

0.012

0.012

3.7

3.7

yellowish green

Tanzania

cabochon, 4.84ct

 

 

 

 

 

 

 

inert

inert

Gems & Gemology 2013 Summer, p122

Kyanite

1.72

1.72

 

 

3.67

3.67

blue

Tanzania

1.72ct, translucent, polycrystalline kyanite, RI indistinct reading of approximately 1.72

 

 

 

 

 

 

 

 

 

The Journal of Gemmology 2014 Vol 34, N°4, p 293

 

TABLES

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

nx min

 nx max

ny min

ny max

nz min

nz max

Reference

Kyanite

1.708

1.735

0.013

0.02

3.55

3.75

 

 

 

 

 

 

Gemmo.eu 

Kyanite

1.71

1.739

0.015

0.019

3.56

3.68

1.710

1.716

 

 

1.727

1.739

Bestimmungstabellen für Edelsteine, Birgit Günther, 2008 

Kyanite

1.71

1.734

0.015

0.02

3.56

3.69

1.710

1.718

1.715

1.725

1.726

1.734

http://www.geminterest.com 

Kyanite

1.71

1.736

0.012

0.017

3.53

3.7

1.710

1.718

 

 

1.727

1.736

Gemme, Dati per l'identificazione, P. De Stefano et al, 1993 

Kyanite

1.71

1.732

0.017

0.021

3.55

3.68

1.710

1.715

1.719

1.726

1.729

1.732

Gemmological Tables, Ulrich Henn, 2004 

Kyanite

1.71

1.753

0.017

0.033

3.53

3.7

 

 

 

 

 

 

http://www.gemmology.be 

Kyanite

1.71

1.753

0.017

0.017

3.53

3.68

1.710

1.718

1.721

1.730

1.727

1.734

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Kyanite

1.71

1.734

0.015

0.017

3.53

3.68

1.710

1.718

1.721

1.723

1.727

1.734

Tables of Gemstone Identification, Roger Dedeyne, Ivo Quintens, 2007 

Kyanite-Cr

1.711

1.753

0.018

0.033

3.56

3.7

1.711

1.720

1.719

1.730

1.729

1.753

http://www.geminterest.com 

Kyanite

1.712

1.735

0.015

0.017

3.56

3.68

1.712

1.720

 

 

1.727

1.735

Tabellen zur Edelstein-Bestimmung, Pschichholz FGA, 1975 

Kyanite

1.712

1.735

0.012

0.017

3.56

3.69

 

 

 

 

 

 

Gemology Tools Professional 2010

Kyanite-Cr

1.714

1.753

0.017

0.033

3.67

3.7

1.714

1.720

1.724

1.730

1.731

1.753

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Kyanite-Cr

1.714

1.753

0.017

0.033

3.67

3.7

1.714

1.720

1.724

1.730

1.731

1.753

Tables of Gemstone Identification, Roger Dedeyn, Ivo Quintens, 2007 

Kyanite

1.715

1.732

0.012

0.015

 

 

 

 

 

 

 

 

John Sinkakas, Gemstone and mineral data book,1972 

Kyanite

1.715

1.732

0.017

0.017

3.65

3.68

 

 

 

 

 

 

Gems, R Webster, 5th edition 1994 

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Kyanite

blue

Fe²+ -O-Ti4+ charge transfer; Fe³+-O-Ti3+ charge transfer; Fe²+ and Fe³+ in octahedral coordination; with contribution from Cr³+  in octahedral coordination

Gems & Gemology Summer 1988

Kyanite

colour change

Cr³+  in octahedral coordination

Gems & Gemology Summer 1988

Kyanite

green

V³+   in octahedral coordination; Fe³+  in octahedral coordination

Gems & Gemology Summer 1988

Kyanite

orange

Mn³+

Gems & Gemology Summer 2009, p147

Kyanite

yellow-green

Fe³+

http://minerals.caltech.edu

 

MINERAL INCLUSIONS

Inclusion

Stone

Reference

andalusite

Kyanite

The Journal of Gemmology 1988, Vol21, N°2,p83-87

apatite

Kyanite

The Journal of Gemmology 1988, Vol21, N°2,p83-87

calcite

Kyanite

The Journal of Gemmology 1988, Vol21, N°2,p83-87

hematite

Kyanite

The Journal of Gemmology 1995, 24,8, p577

ilmenite

Kyanite

The Australian Gemmologist 2004, Vol 22, N°1, p36

lepidocrocite

Kyanite

The Journal of Gemmology 1988, Vol21, N°2,p83-87

monazite

Kyanite

The Journal of Gemmology 1981, Vol 17, N°6 p379

quartz

Kyanite

Gems & Gemology 2002 Summer, p179

rutile

Kyanite

www.geminterest.com

spessartine

Kyanite

E.J. Gübelin and J.I. Koivula, Photoatlas of inclusions in Gemstones, volume 2 (2005)

staurolite

Kyanite

E.J. Gübelin and J.I. Koivula, Photoatlas of inclusions in Gemstones, volume 2 (2005)

tourmaline

Kyanite

Gems & Gemology 2002 Summer, p179

zircon

Kyanite

www.geminterest.com

 

LOCALITIES

STONE

LOCALITIES

REFERENCE

Kyanite

 

 

Bahia

Brazil

Gems & Gemology 2001 winter p338

Kyanite-Cr

 

 

 

Madagascar

Gems & Gemology 2007 fall, p256

Kyanite

 

Serra do Menucué

 

Mozambique

Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 422

Kyaniet

 

 

 

Nepal

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 2012, Dez, p91-97

Kyanite

Kilosa, 80 km west of Morogoro

 

 

Tanzania

Gemmologie, 1997, Mar, p31

Kyanite

 

 

Arusha region

Tanzania

Gems & Gemology 2004 winter p341

Kyanite

Merelani Hills, Umba Valley

Lelatema Mts

Arusha region

Tanzania

Gemmologie, 1997, Mar, p31

Kyanite

Umba Valley

Lelatema Mts

Arusha region

Tanzania

Gemmologie, 1997, Mar,p31

Kyanite

Loliondo

Ngorongoro district

Arusha region

Tanzania

Gems & Gemology 2009 summer, p146-147

Kyanite

 

Tunduru-Songea area

Ruvuma Region

Tanzania

Gemmologie, 1997, Mar,p31

 

CHEMICAL DATA (%)

Stone

Colour

Locality

Reference

SiO2

Al2O3

TiO2

CaO

K2O

Cr2O3

V2O3

Fe2O3

Kyanite

cat's eye

 

East Africa

The Journal of Gemmology 1995, Vol 24, N°8, p 574

37.7

61.79

0.4

0.05

0.1

 

 

 

Kyanite

greyish

 

 

The Journal of Gemmology 1988, Vol 21, N°2, p84

37.58

62.19

0.21

0.07

0.05

 

 

 

Kyanite

blue

 

Nepal

Gemmologie zeitschrift der Deutschen Gemmologischen Gesellschaft 2012, Dez, p94

34.2

65.03

0.02

 

 

0.03

0.02

0.13