|
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 |
Omphacite |
1.667 |
1.67 |
|
|
3.34 |
3.44 |
black or blackish
green |
|
called inky jadeite jade,
>80% omphacite |
|
|
|
|
|
|
|
inert |
inert |
The Journal of Gemmology 2003
Vol28, N°6, p337-344 |
Omphacite |
1.67 |
1.68 |
|
|
3.33 |
3.41 |
dark greenish blue, dark blue,
greyish greenish blue |
Quebrada Seca, Jalapa
Department, Guatemala |
translucent |
|
|
|
|
|
|
nihil |
inert |
inert |
Gems & Gemology 2004 spring,
p68 |
Omphacite |
1.67 |
1.68 |
|
|
3.35 |
3.36 |
dark
green |
Po Valley, Piemonte,
Italy |
hardness 6.5, jade,
translucent |
|
|
|
|
|
|
|
inert |
inert |
The Journal of Gemmology 2006
Vol 30, No3/4 p
215-226 |
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 |
Omphacite |
1.662 |
1.723 |
0.023 |
0.023 |
3.29 |
3.39 |
1.662 |
1.701 |
1.670 |
1.712 |
1.685 |
1.723 |
Tables of Gemstone
Identification, Roger Dedeyn, Ivo Quintens, 2007
|
CAUSE OF COLOUR
MINERAL INCLUSIONS
LOCALITIES
CHEMICAL DATA (%)
Stone |
Colour |
Locality |
Reference |
SiO2 |
Al2O3 |
MnO |
MgO |
FeO |
TiO2 |
CaO |
Na2O |
Cr2O3 |
Fe2O3 |
K2O | |
Omphacite |
|
Po Valley |
Italy |
The Journal of Gemmology 2006,
3/4, p221 |
55.86 |
13.23 |
0.13 |
6.38 |
1.14 |
0.22 |
8.27 |
9.94 |
0.17 |
5.17 |
0.01 |
Omphacite |
|
Po Valley |
Italy |
The Journal of Gemmology 2006,
3/4, p221 |
55.44 |
11.96 |
0.12 |
8.37 |
1.38 |
0.14 |
11.22 |
8.29 |
0.29 |
2.6 |
|
Omphacite |
|
|
|
The Journal of Gemmology 2003,
Vol 28,N°6, p342 |
56.45 |
11.19 |
|
7.84 |
3.97 |
|
11.84 |
7.91 |
0.16 |
|
|