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INVESTIGATIONS

Stone

RI min

RI max

Dens min

Dens max

Colour

Location

Info

Spectrum

UVS

UVL

Reference

Copal

1.53

1.53

1.05

1.05

 

 

5.56ct, cabochon, spot RI

 

greenish

 

ACAM lab  1930

Copal

1.54

1.54

1.03

1.095

colourless, red-brown

New Zealand

transparent to opaque, Kauri copal; alchol solubility test gives better results than ether

 

inert to light blue , white and mustard

stronger than UVS

The Journal of Gemmology 1997 Vol 25, N6, p408-416

 

TABLES

Stone

RI min

RI max

Dens min

Dens max

Reference

Copal

1.52

1.54

1.04

1.1

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

Copal

1.53

1.54

2.03

1.1

http://www.geminterest.com 

Copal

1.53

1.54

1.03

1.1

Gemology Tools Professional 2010

Copal

1.535

1.545

1.03

1.12

www.gemmo.eu 

Copal

1.539

1.545

1.05

1.1

Gemmological Tables, Ulrich Henn, 2004 

Copal

1.539

1.545

1

1.1

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

Copal

1.54

1.542

1.03

1.1

http://www.gemmology.be 

Copal

1.54

1.54

1.03

1.1

Gems, R Webster, 5th edition 1994 

 

CAUSE OF COLOUR

Stone

Colour

Cause of colour

Reference

Copal

yellow, brown

charge transfer processes in large organic molecules

Gems & Gemology Summer 1988

 

MINERAL INCLUSIONS

 

LOCALITIES

 

CHEMICAL DATA