|
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 |
|
Montebrasite |
1.6 |
1.62 |
0.02 |
0.02 |
|
|
pale purple |
Afghanistan |
3.79ct |
|
|
|
|
|
|
|
|
|
The Journal of Gemmology 2018 36(4), p286 |
|
Montebrasite |
1.61 |
1.635 |
0.025 |
0.025 |
2.96 |
2.96 |
yellowish green, transparent |
Brazil |
0.49ct |
|
|
|
|
|
|
|
|
|
Gemmologie, Zeitschrift der Deutschen
Gemmologischen Gesellschaft 2008 Dec, p117-118 |
|
Montebrasite |
1.612 |
1.639 |
0.027 |
0.027 |
3.03 |
3.03 |
light slightly brownish yellow |
Brazil |
46.28ct |
|
|
|
|
|
|
no features |
inert |
inert |
GIA Gem Database 34258 |
|
Montebrasite |
1.615 |
1.628 |
0.013 |
0.013 |
3.03 |
3.03 |
light yellowish green |
Brazil |
1.34ct, biaxial + |
|
|
|
|
|
|
|
inert |
inert |
GIA Gem Database 35456 |
|
Montebrasite |
1.615 |
1.644 |
0.029 |
0.029 |
3.03 |
3.03 |
light yellow, almost colourless |
|
2.16 ct |
1.615 |
1.615 |
1.623 |
1.623 |
1.644 |
1.644 |
|
|
weak violet |
ACAM Lab
n°871 |
|
Montebrasite |
1.616 |
1.645 |
0.029 |
0.029 |
3.02 |
3.02 |
light greyish green |
Brazil |
biaxial + |
|
|
|
|
|
|
|
|
|
Gemmologie, Zeitschrift der Deutschen
Gemmologischen Gesellschaft 2010 59/3-4, p95-102 |
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 |
|
Montebrasite |
1.593 |
1.647 |
0.02 |
0.03 |
2.96 |
3.11 |
|
|
|
|
|
|
Gemmo.eu 2020 |
|
Montebrasite |
1.594 |
1.633 |
0.021 |
0.026 |
2.98 |
3.03 |
1.594 |
1.611 |
1.603 |
1.619 |
1.615 |
1.633 |
http://www.geminterest.com |
|
Montebrasite |
1.594 |
1.646 |
0.02 |
0.05 |
2.98 |
3.05 |
1.594 |
1.615 |
1.608 |
1.624 |
1.616 |
1.646 |
Tables of Gemstone Identification, Roger Dedeyne, Ivo Quintens, 2007 |
|
Montebrasite |
1.594 |
1.633 |
0.02 |
0.027 |
2.98 |
3.085 |
|
|
|
|
|
|
Gemology Tools Professional 2010 |
|
Montebrasite |
1.611 |
1.633 |
0.022 |
0.022 |
3 |
3 |
|
|
|
|
|
|
Tables of Gemstone Identification, Roger Dedeyne, Ivo Quintens, 2007 |
|
Montebrasite |
1.622 |
1.646 |
0.02 |
0.03 |
2.98 |
3.08 |
|
|
|
|
|
|
http://www.gemmology.be |
CAUSE OF
COLOUR
MINERAL
INCLUSIONS
LOCALITIES
CHEMICAL DATA
(%)
|
Stone |
Colour |
Locality |
Reference |
Al2O3 |
Fe2O3 |
P2O5 |
|
|
Montebrasite |
|
|
Brazil |
Zeitschrift der Deutschen Gemmologischen
Gesellschaft, 2010, Nr 3/4, p99 |
48.4 |
0.02 |
35.15 |