|
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 |
|
thortveitite |
1.753 |
1.809 |
0.056 |
0.056 |
3.48 |
3.48 |
purplish
blue |
|
biaxial
negative |
1.753 |
1.753 |
1.793 |
1.793 |
1.809 |
1.809 |
2 lines at around 535nm and band at
425nm |
none |
none |
The journal of Gemmology 2008 Vol 31/Nos 1/2
/p1-6 |
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 |
|
thortveitite |
1.756 |
1.809 |
0.053 |
0.053 |
3.5 |
3.5 |
|
|
|
|
|
|
Tables of Gemstone Identification, Roger Dedeyn,
Ivo Quintens, 2007
|
CAUSE OF COLOUR
MINERAL INCLUSIONS
LOCALITIES
CHEMICAL DATA (%)