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

Dumortierite

1.67

1.69

3.17

3.4

Madagascar

4 rough pieces, RI spot readings, biaxial negative, lazulite inclusions

strong whitish blue

inert

The Journal of Gemmology 2018 36(2), p 92-93

Dumortierite

1.672

1.69

0.018

0.018

3.42

3.42

blue, transparent

Sri Lanka

very weak chalky green

inert

Gems & Gemology 2000 spring p62

Dumortierite

1.673

1.69

0.017

0.017

violetish blue

Madagascar

0.42ct

very strong: bluish-white

inert

www.spec4gem.info 2018 10 dec

Dumortierite

1.679

1.709

0.03

0.03

3.38

3.41

violet grey, brownish pink

Tunduru, Tanzania

transparent!

1.679

1.679

1.709

1.709

white

inert

Gems & Gemology 2007 winter, p379

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

Dumortierite

1.65

1.723

0.014

0.037

3.2

3.42

1.650

1.686

1.682

1.722

1.685

1.723

http://www.geminterest.com 

Dumortierite

1.668

1.723

0.012

0.037

3.26

3.41

1.668

1.693

1.685

1.723

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

Dumortierite

1.668

1.723

0.015

0.037

3.26

3.41

1.668

1.686

1.682

1.722

1.685

1.723

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Dumortierite

1.668

1.688

0.011

0.011

3.26

3.41

1.668

1.673

1.685

1.688

Gems, R Webster, 5th edition 1994 

Dumortierite

1.668

1.688

0.015

0.037

3.31

3.35

1.668

1.673

1.682

1.684

1.685

1.688

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

Dumortierite

1.669

1.723

0.015

0.037

3.31

3.31

1.669

1.686

1.682

1.722

1.685

1.723

Gemmological Tables, Ulrich Henn, 2004 

Dumortierite

1.67

1.689

0.011

0.016

3.2

3.4

Bestimmungstabellen für Edelsteine, Birgit Günther, 1981 

Dumortierite

1.67

1.728

0.014

0.038

3.2

3.45

Gemmo.eu 2019

Dumortierite

1.678

1.723

0.015

0.037

3.2

3.48

1.678

1.686

1.684

1.722

1.686

1.723

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

Dumortierite

1.68

1.68

3.26

3.36

John Sinkakas, Gemstone and mineral data book,1972 

Dumortierite

1.686

1.723

0.015

0.037

3.26

3.41

http://www.gemmology.be 

Dumortierite

1.686

1.723

0.037

0.037

3.26

3.42

Tabellen zur Edelstein-Bestimmung, Pschichholz FGA, 1975 

Stone

Colour

Cause of colour

Reference

Dumortierite

blue, pink

The color of dumortierite is usually due to its iron and titanium content. Although the exact origin of color is still under investigation.

http://minerals.caltech.edu

Inclusion

Stone

Reference

lazulite

Dumortierite

The Journal of Gemmology 2018 Vol 35 - 2, p95

STONE

LOCALITIES

REFERENCE

Dumortieriet

Departementa Ambatofinandrahana, Amoron'i Mania region

Fianarantsoa Province

Madagascar

Gemmologie, Dez 1999,p196

Dumortieriet

Tunduru

Ruvuma Region

Tanzania

Gems & Gemology 2007 Winter, p379