|
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 |
Tephroite |
1.778 |
|
|
|
4.05 |
4.05 |
greenish grey in daylight and red-brown in incandescent light |
|
0.56ct and 6.25ct, colour-change |
|
|
|
|
|
|
absorptions at 420, 456, 499 and 587 nm |
inert |
inert |
The Journal of Gemmology 2018 36(4), p292 |
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 |
Tephroite |
1.769 |
1.826 |
0.036 |
0.048 |
3.87 |
4.4 |
|
|
|
|
|
|
Gemmo.eu 2020 |
Tephroite |
1.77 |
1.825 |
0.037 |
0.047 |
4.11 |
4.11 |
|
|
|
|
|
|
http://www.gemmology.be |
Tephroite |
1.77 |
1.825 |
0.037 |
0.047 |
4.11 |
4.11 |
1.770 |
1.788 |
1.807 |
1.810 |
1.817 |
1.825 |
Joel Arem, Color Encyclopedia of Gemstones, 1987 |
Tephroite |
1.77 |
1.825 |
0.027 |
0.047 |
3.72 |
4.33 |
1.770 |
1.788 |
1.807 |
1.810 |
1.817 |
1.825 |
http://www.geminterest.com |
Tephroite |
1.77 |
1.825 |
0.037 |
0.047 |
4.11 |
4.11 |
1.770 |
1.788 |
1.807 |
1.810 |
1.817 |
1.825 |
Tables of Gemstone Identification, Roger Dedeyne, Ivo Quintens, 2007 |
CAUSE OF
COLOUR
MINERAL
INCLUSIONS
LOCALITIES
CHEMICAL DATA
(%)