|
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 |
|
Danburite |
1.628 |
1.638 |
0.01 |
0.01 |
3.01 |
3.01 |
colourless |
|
2.06ct |
1.628 |
1.628 |
1.632 |
1.632 |
1.638 |
1.638 |
|
light blue |
inert |
ACAM lab
1065 |
|
Danburite |
1.628 |
1.637 |
0.006 |
0.008 |
2.97 |
3.01 |
vivid yellow |
Namalulu region, Tanzania |
1 to 18ct |
1.628 |
1.629 |
1.631 |
1.634 |
1.634 |
1.637 |
|
inert |
inert |
The Journal of Gemmology 2017 Vol35, N°5, p381-384 |
|
Danburite |
1.628 |
1.633 |
0.005 |
0.005 |
3.01 |
3.01 |
brownish yellowish orange |
Madagascar |
30.37ct |
|
|
|
|
|
|
no features |
inert |
inert |
GIA Gem Database 34390 |
|
Danburite |
1.629 |
1.638 |
0.007 |
0.009 |
2.97 |
3.01 |
yellow |
Tanzania |
|
1.629 |
1.631 |
|
|
1.638 |
1.638 |
none |
inert |
inert |
Gems & Gemology 2008 summer p169-171 |
|
Danburite |
1.629 |
1.636 |
0.007 |
0.007 |
2.99 |
2.99 |
yellow |
Morogoro, Tanzania |
8.86ct |
1.629 |
1.629 |
1.632 |
1.632 |
1.636 |
1.636 |
line at 585nm |
|
|
http://www.geminterest.com 2008 |
|
Danburite |
1.629 |
1.632 |
0.003 |
0.003 |
3.01 |
3.01 |
yellow-green |
Mogok, Myanmar |
|
|
|
|
|
|
|
lines at 569, 571, 579, 585, 588nm |
weak violet |
weak blue |
GIA Gem Database 34557 |
|
Danburite |
1.629 |
1.633 |
0.004 |
0.004 |
3 |
3 |
orangy yellow |
Kolonne, Sri Lanka |
6.37ct |
|
|
|
|
|
|
no features |
inert |
inert |
GIA Gem Database 34810 |
|
Danburite |
1.63 |
1.636 |
0.009 |
0.009 |
3 |
3 |
green |
Momeik (Molo) , Mogok, Myanmar |
|
|
|
|
|
|
|
|
weak |
weak |
The Australian Gemmologist 2005 22,
p303-309 |
|
Danburite |
1.63 |
1.638 |
0.008 |
0.008 |
3 |
3 |
golden yellow |
Sri Lanka |
|
|
|
|
|
|
|
line at 585nm |
inert |
inert |
Gems & Gemology 1986 spring p47 |
|
Danburite |
1.63 |
1.636 |
0.006 |
0.006 |
2.99 |
2.99 |
colourless |
Dalnegorsk, Russia |
|
|
|
|
|
|
|
|
|
|
Gemmologie, Zeitschrift der Deutschen
Gemmologischen Gesellschaft 1998 Sep, p171 |
|
Danburite |
1.63 |
1.636 |
0.006 |
0.006 |
3 |
3 |
dark yellowish orange |
Russia |
6.51ct, biaxial + |
|
|
|
|
|
|
broad absorption below 530nm |
inert |
inert |
GIA Gem Database 35375 |
|
Danburite |
1.63 |
1.636 |
0.006 |
0.006 |
3.01 |
3.01 |
orangy yellow |
Anjanabonoina Mine, Ambohimanambola, Antananarivo Province, Madagascar |
15.81ct |
|
|
|
|
|
|
|
inert |
weak green |
GIA Gem Database 34391 |
|
Danburite |
1.63 |
1.634 |
0.004 |
0.004 |
|
|
yellow |
Mogok, Myanmar |
|
|
|
|
|
|
|
|
blue |
blue |
Gems & Gemology 2007 Summer,
p167-168 |
|
Danburite |
1.63 |
1.637 |
0.006 |
0.008 |
2.98 |
3.01 |
honey yellow |
Luc Yen mining area, Vietnam |
4.6ct |
1.630 |
1.632 |
1.633 |
1.635 |
1.636 |
1.637 |
|
inert |
strong blue |
Gems & Gemology 2016 Winter,
p393-401 |
|
Danburite |
1.63 |
1.636 |
0.006 |
0.006 |
3.01 |
3.01 |
colourless |
Mexico |
6.78ct |
|
|
|
|
|
|
no features |
weak green |
inert |
GIA Gem Database 34451 |
|
Danburite |
1.63 |
1.636 |
0.006 |
0.006 |
30 |
3 |
yellow |
Ratnapura, Sri Lanka |
11.12ct |
|
|
|
|
|
|
no features |
inert |
inert |
GIA Gem Database 34808 |
|
Danburite |
1.631 |
1.639 |
0.008 |
0.008 |
2.95 |
2.95 |
colourless |
Sri Lanka |
1.58ct |
|
|
|
|
|
|
|
|
|
Gemmologie, Zeitschrift der Deutschen
Gemmologischen Gesellschaft 1999 Jul p106 |
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 |
|
Danburite |
1.624 |
1.641 |
0.004 |
0.01 |
2.93 |
3.06 |
|
|
|
|
|
|
Gemmo.eu
|
|
Danburite |
1.627 |
1.641 |
0.006 |
0.008 |
2.9 |
3.01 |
1.627 |
1.633 |
1.630 |
1.637 |
1.633 |
1.641 |
Gemmological Tables, Ulrich Henn,
2004 |
|
Danburite |
1.627 |
1.639 |
0.006 |
0.006 |
2.99 |
3.01 |
1.627 |
1.633 |
|
|
1.633 |
1.639 |
Tabellen zur Edelstein-Bestimmung,
Pschichholz FGA, 1975 |
|
Danburite |
1.627 |
1.633 |
0.006 |
0.006 |
2.97 |
3.03 |
|
|
|
|
|
|
Gemology Tools Professional 2010 |
|
Danburite |
1.628 |
1.641 |
0.004 |
0.008 |
2.97 |
3.03 |
1.628 |
1.633 |
1.630 |
1.637 |
1.633 |
1.641 |
Tables of Gemstone Identification, Roger Dedeyne,
Ivo Quintens, 2007 |
|
Danburite |
1.63 |
1.641 |
0.006 |
0.008 |
2.97 |
3.03 |
1.630 |
1.633 |
|
|
1.633 |
1.641 |
Gemme, Dati per l'identificazione, P. De
Stefano et al, 1993 |
|
Danburite |
1.63 |
1.641 |
0.006 |
0.008 |
2.97 |
3.03 |
|
|
|
|
|
|
http://www.gemmology.be |
|
Danburite |
1.63 |
1.641 |
0.006 |
0.008 |
2.9 |
3.1 |
1.630 |
1.633 |
1.633 |
1.637 |
1.636 |
1.641 |
http://www.geminterest.com |
|
Danburite |
1.63 |
1.641 |
0.006 |
0.008 |
2.97 |
3.03 |
1.630 |
1.633 |
1.633 |
1.637 |
1.636 |
1.641 |
Joel Arem, Color Encyclopedia of Gemstones,
1987 |
|
Danburite |
1.63 |
1.636 |
0.006 |
0.006 |
3 |
3 |
|
|
|
|
|
|
Gems, R Webster, 5th edition 1994 |
|
Danburite |
1.63 |
1.64 |
0.006 |
0.008 |
2.99 |
3.01 |
1.630 |
1.633 |
|
|
1.633 |
1.640 |
Bestimmungstabellen für Edelsteine,
Birgit Günther, 2008 |
|
Danburite |
|
|
0.006 |
0.006 |
2.99 |
3 |
|
|
|
|
|
|
John Sinkakas, Gemstone and mineral data
book,1972 |
CAUSE OF
COLOUR
|
Stone |
Colour |
Cause of
colour |
Reference |
|
Danburite |
greenish-yellow |
in part from rare-earths |
http://minerals.caltech.edu |
|
Danburite |
yellow |
assumed that lanthanides are responsible for the yellow colour, the
intesity may be linked to variable ratios of the valence states of certain
lanthanides |
The Journal of Gemmology 2017, 35 (5) p384-386 |
MINERAL
INCLUSIONS
|
Inclusion |
Stone |
Reference |
|
nifontovite |
Danburite |
E.J. Gübelin and J.I. Koivula, Photoatlas of inclusions in Gemstones,
volume 3 |
|
nontronite |
Danburite |
E.J. Gübelin and J.I. Koivula, Photoatlas of inclusions in Gemstones,
volume 3 |
|
pyrite |
Danburite |
The Gem Trader |
|
sillimanite |
Danburite |
E.J. Gübelin and J.I. Koivula, Photoatlas of inclusions in Gemstones,
volume 3 |
LOCALITIES
|
STONE |
LOCALITIES |
REFERENCE |
|||
|
Danburite |
Obira mine |
Ono-gun |
Oita Prefecture |
Japan |
Michael O'Donoghue, Gems: Their Sources, Descriptions and Identification
(2006), 873pp |
|
Danburite |
|
|
|
Madagascar |
Joel Arem, Color Encyclopedia of Gemstones, 1987 |
|
Danburite |
|
Vakinankaratra Region (Betafo -
Antsirabé region) |
Antananarivo Province |
Madagascar |
Gemmologie, Dez 1999,p196 |
|
Danburite |
San Sebastian Mine |
Charcas |
San Luis Potosi |
Mexico |
Lapis 1993/3 |
|
Danburite |
Momeik |
Mogok |
Mandalay |
Myanmar |
The Australian Gemmologist (2005) 22,
p308 |
|
Danburite |
Hyakule |
Sankhuwasabha District (Sankhuwa Sahba) |
Kosi Zone |
Nepal |
Zeitschrift der Deutschen Gemmologischen
Gesellschaft, 1993, Sep, p78 |
|
Danburite |
|
Luc Yen |
Yenbai (Yen Bai) Province |
Vietnam |
Gems & Gemology Winter 2016,
p393-401 |
CHEMICAL DATA
|
Stone |
Colour |
Locality |
Reference |
SiO2 |
CaO |
B2O3 |
|
|
Danburite |
yellow |
Luc Yen |
Vietnam |
Gems & Gemology 2016 Winter, p396 |
46.6 |
22.7 |
31.4 |
|
Danburite |
yellow |
Luc Yen |
Vietnam |
Gems & Gemology 2016 Winter, p396 |
47.3 |
22.7 |
31.5 |