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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

Andalusite

1.63

1.641

0.011

0.011

3.21

3.21

greenish brown

Sri Lanka

1.97ct

 

 

 

 

 

 

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1998 Sep, p169

Andalusite

1.63

1.64

0.01

0.01

3.16

3.16

greenish yellow

Brazil

13.22 ct, biaxial -

 

 

 

 

 

 

442, 457nm

inert

inert

GIA Gem Database  33922

Andalusite

1.63

1.643

0.013

0.013

3.17

3.17

green-brown

 

0.95 ct

1.634

1.634

 

 

1.643

1.643

 

inert

inert

ACAM Lab  N1313

Andalusite

1.63

1.63

0.013

0.013

3.19

3.19

brownish green-red

 

0.46 ct

1.630

1.630

1.639

1.639

1.643

1.643

 

inert

inert

ACAM Lab  N4414

Andalusite

1.63

1.64

0.01

0.01

3.16

3.16

greenish brown

 

0.38ct

1.630

1.630

1.639

1.639

1.640

1.640

 

yellowish green

inert

ACAM Lab  N4460

Andalusite

1.63

1.658

0.028

0.28

3.18

3.18

brown

 

1 ct

1.630

1.630

1.646

1.646

1.658

1.658

 

inert

olive green

ACAM Lab  N1022

Andalusite

1.63

1.644

0.014

0.014

3.23

3.23

greenish pink

 

0.42 ct

1.630

1.630

1.637

1.637

1.644

1.644

 

inert

yellow-reen

ACAM Lab  N188

Andalusite

1.63

1.641

0.011

0.011

3.16

3.16

brown-green

 

0.38ct

1.630

1.630

1.638

1.638

1.641

1.641

 

inert

inert

ACAM Lab  N4459

Andalusite

1.63

1.63

 

 

3.13

3.13

mottled purplish pinkish brown bodycolor with black "spokes"

 

sphere 26.33mm, opaque "chiastolite"

 

 

 

 

 

 

 

 

 

Gems & Gemology 1998 Spring, p51

Andalusite

1.631

1.64

0.009

0.009

3.16

3.16

greenish yellow

Espirito Santo, Brazil

16.71ct

 

 

 

 

 

 

 

inert

inert

GIA Gem Database  34263

Andalusite

1.632

1.646

0.01

0.011

3.15

3.15

green+colourless and green/pink

Santa Tereza, Espirito Santo, Brazil

20.71 ct

1.632

1.635

1.637

1.640

1.642

1.646

 

 

 

Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 1996 Dec, p153

Andalusite

1.633

1.64

0.007

0.007

3.16

3.16

greenish yellow

Espirito Santo, Brazil

14.41ct

 

 

 

 

 

 

442, 458nm

weak green

inert

GIA Gem Database  33924

Andalusite

1.633

1.647

0.014

0.014

3.17

3.17

olive green

Brazil

 

 

 

 

 

 

 

 

 

 

The Journal of Gemmology 1983 Vol18, N7, p581-591

Andalusite

1.634

1.645

0.011

0.011

3.15

3.17

olive-green to yellow-green

Maricota, Minas Gerais, Brazil

 

 

 

 

 

 

 

weak band 455nm

pale mustard

 

Revue de  Gemmologie A.F.G. 1989 Sep, N 100, p7-9

Andalusite

1.634

1.643

0.009

0.009

3.33

3.33

brownish

 

0.4 ct

1.634

1.634

1.638

1.638

1.643

1.643

cut-off 440nm

inert

inert

ACAM Lab  N1312

Andalusite

1.635

1.635

0.02

0.02

3.28

3.28

light brown

 

0.59 ct

1.635

1.635

1.642

1.642

1.655

1.655

 

yellow

inert

ACAM Lab  N105

Andalusite

1.637

1.654

0.008

0.01

3.11

3.16

green, yellowish green to brownish green, brownish pink, bicoloured green/pink, pinkish brown

Brazil

transparent to opaque

1.637

1.649

 

 

1.646

1.654

diffuse band at 455

inert

moderate to strong yellowish green

Gems & Gemology 2009 Summer, p120-129

Andalusite

1.638

1.652

0.014

0.014

3.12

3.12

greenish

 

0.19 ct

 

 

 

 

 

 

555nm, 520nm line

inert

inert

ACAM Lab  N4741

Andalusite

1.638

1.649

0.011

0.011

 

 

yellow green to peridot green

Chapada Diamantina, Bahia, Brazil

 

 

 

 

 

 

 

 

inert

inert

Revue de  Gemmologie A.F.G. 1980 N63, p15-17

Andalusite

1.64

1.648

0.008

0.008

3.28

3.28

dark green

Brazil

0.19ct

 

 

 

 

 

 

555nm, 520nm line

inert

inert

ACAM Lab  N4742

 

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

Andalusite

1.627

1.651

0.007

0.013

3.05

3.2

1.627

1.642

 

 

1.640

1.651

Bestimmungstabellen fr Edelsteine, Birgit Gnther, 2008 

Andalusite

1.627

1.65

0.007

0.013

3.05

3.2

1.627

1.642

 

 

1.638

1.650

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

Andalusite

1.627

1.649

0.007

0.011

3.05

3.2

 

 

 

 

 

 

http://www.gemmology.be 

Andalusite

1.628

1.65

0.007

0.013

3.05

3.2

1.628

1.640

1.633

1.644

1.638

1.650

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

Andalusite

1.629

1.66

0.007

0.013

3.05

3.2

1.629

1.649

1.633

1.653

1.638

1.660

Gemmological Tables, Ulrich Henn, 2004 

Andalusite

1.629

1.652

0.007

0.016

3.12

3.18

1.629

1.640

1.633

1.646

1.638

1.652

http://www.geminterest.com 

Andalusite

1.629

1.65

0.007

0.011

3.13

3.17

1.629

1.640

1.633

1.644

1.638

1.650

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Andalusite

1.629

1.648

0.007

0.013

3.13

3.21

 

 

 

 

 

 

Gemology Tools Professional 2010

Andalusite

1.629

1.651

0.009

0.014

3.1

3.2

 

 

 

 

 

 

Gemmo.eu 2013

Andalusite

1.633

1.648

0.007

0.012

3.12

3.21

1.633

1.642

 

 

1.643

1.648

Tabellen zur Edelstein-Bestimmung, Pschichholz FGA, 1975 

Andalusite

1.634

1.648

0.009

0.01

3.1

3.2

 

 

 

 

 

 

John Sinkakas, Gemstone and mineral data book,1972 

Andalusite

1.634

1.648

0.007

0.011

3.15

3.17

1.634

1.641

 

 

1.644

1.648

Gems, R Webster, 5th edition 1994 

Andalusite viridine

1.66

1.69

0.029

0.029

 

 

 

 

 

 

 

 

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Andalusite viridine

1.66

1.689

0.029

0.029

3.05

3.2

 

 

 

 

 

 

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

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Andalusite viridine

dark green

Mn+ in octahedral coordination

Gems & Gemology Summer 1988

Andalusite

green, brown

charge transfer Fe+-O-Ti4+

Gems & Gemology Summer 1988

Andalusite

yellowish green

Fe+

http://minerals.caltech.edu

 

MINERAL INCLUSIONS

Inclusion

Stone

Reference

apatite

Andalusite

Gems & Gemology 1980 Winter p401-404

biotite

Andalusite

Gems & Gemology 1980 Winter p401-404

hematite

Andalusite

Revue de  Gemmologie A.F.G., 1989, Sep, N100, p7-9

limonite

Andalusite

Gems & Gemology 1980 Winter p401-404

quartz

Andalusite

Gems & Gemology 1980 Winter p401-404

rutile

Andalusite

Internal World of Gemstones, Gbelin, 1983

sillimanite

Andalusite

Revue de  Gemmologie A.F.G., 1989, Sep, N100, p7-9

 

LOCALITIES

STONE

LOCALITIES

REFERENCE

Andalusite

Merelani Hills (Mererani), Umba Valley

Lelatema Mts

Arusha Region

Tanzania

Gemmologie, 1997, Mar, p31

Andalusite

 

Santa Teresa

Espirito Santo

Brazil

Gemmologie 1996, Dec, p153