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INVESTIGATIONS

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

Colour

Location

Info

ne min

ne max

no min

no max

Spectrum

UVS

UVL

Reference

Willemite

1.695

1.723

0.028

0.028

 

 

very light yellow to slightly brown

Franklin mining district, New Jersey, USA

0.42ct

 

 

 

 

 

strong yellowish-green

inert

www.spec4gem.info 2019 13 january

Willemite

1.696

1.724

0.028

0.028

4.29

4.29

orange

Franklin District, Sussex County, New Jersey, USA

10.15ct

 

 

 

 

broad absorption below 425; lines at 490, 550nm

weak green

inert

GIA Gem Database  34123

Willemite

1.699

1.721

0.022

0.022

4.24

4.24

orangy yellow

Franklin District, Sussex County, New Jersey, USA

9.54ct

 

 

 

 

broad absorption below 415; lines at 428, 440, 452, 480, 500nm

medium green

medium green

GIA Gem Database  35546

 

TABLES

Stone

RI min

RI max

Biref min

Biref max

Dens min

Dens max

ne min

ne max

no min

no max

Reference

Willemite

1.687

1.723

0.028

0.029

3.89

4.18

1.716

1.723

1.687

1.695

Gemmological Tables, Ulrich Henn, 2004 

Willemite

1.688

1.726

0.021

0.031

3.88

4.27

 

 

 

 

Gemmo.eu 2019

Willemite

1.69

1.723

0.028

0.033

3.89

4.2

1.719

1.723

1.690

1.691

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

Willemite

1.69

1.72

0.03

0.03

3.89

4.18

 

 

 

 

Tabellen zur Edelstein-Bestimmung, Pschichholz FGA, 1975 

Willemite

1.69

1.72

0.028

0.028

3.89

4.18

 

 

 

 

Gems, R Webster, 5th edition 1994 

Willemite

1.69

1.723

0.028

0.033

3.89

4.18

1.719

1.723

1.690

1.691

Bestimmungstabellen für Edelsteine, Birgit Günther, 2008 

Willemite

1.69

1.715

0.01

0.033

3.89

4.18

1.715

1.730

1.690

1.720

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

Willemite

1.691

1.719

0.028

0.028

3.89

4.1

1.719

1.719

1.691

1.691

Joel Arem, Color Encyclopedia of Gemstones, 1987 

Willemite

1.691

1.719

0.028

0.028

3.89

4.1

 

 

 

 

http://www.gemmology.be 

Willemite

1.691

1.72

0.018

0.028

3.9

4.18

 

 

 

 

John Sinkakas, Gemstone and mineral data book,1972 

Willemite

1.691

1.719

0.028

0.028

3.89

4.18

1.719

1.719

1.691

1.691

http://www.geminterest.com 

Willemite

1.691

1.719

0.028

0.028

4

4.2

 

 

 

 

Gemology Tools Professional 2010

Willemite

1.691

1.724

0.028

0.028

3.89

4.1

1.719

1.724

1.691

1.695

Michael O'Donoghue, Gems: Their Sources, Descriptions and Identification (2006),  873pp 

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Willemite

yellow, yellow-green

Mn²+ in tetrahedral coordination

Gems & Gemology Summer 1988

 

MINERAL INCLUSIONS

 

LOCALITIES

STONE

LOCALITIES

REFERENCE

Willemite

Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry)

Mont Saint-Hilaire, Rouville County

Quebec

Canada

Zeitschrift der Deutschen Gemmologischen Gesellschaft, 1994, Dez, p137







 

CHEMICAL DATA (%)