|
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 |
|
Manganotantalite |
2.16 |
2.16 |
|
|
7.73 |
7.97 |
scarlet red |
Morrua, Mozambique |
0.58ct, strong dispersion, somewhat metallic luster |
|
|
|
|
|
|
broad band in yellow-green and in the violet |
inert |
inert |
The Journal of Gemmology 1979 Vol 16, N°6, p363-364 |
|
Manganotantalite |
|
|
|
|
7.76 |
7.81 |
dark red |
Grangal, Nuristan, Afghanistan |
1.10ct and 4.66ct, strong doubling of facets |
|
|
|
|
|
|
|
inert |
inert |
The Journal of Gemmology 2016 Vol 35, No. 2,
p111-114 |
|
Manganotantalite |
|
|
|
|
7.8 |
7.8 |
red-orange |
Pakistan |
9.90ct |
|
|
|
|
|
|
broad absorption below 500nm and between 540-580 |
inert |
inert |
GIA Gem Database 35449 |
|
Manganotantalite |
|
|
|
|
8 |
8 |
red |
Murrua, Zambezia Province, Mozambique |
5.51ct |
|
|
|
|
|
|
broad absorption below 490nm and between 540-585 |
inert |
inert |
GIA Gem Database 35448 |
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 |
|
Manganotantalite |
2.13 |
2.25 |
0.14 |
0.16 |
7.5 |
8 |
|
|
|
|
|
|
Gemmo.eu 2016 |
|
Manganotantalite |
2.14 |
2.34 |
0.08 |
0.15 |
7.73 |
7.97 |
2.140 |
2.190 |
2.150 |
2.250 |
2.220 |
2.340 |
http://www.geminterest.com |
|
Manganotantalite |
2.14 |
2.34 |
0.008 |
0.015 |
7.73 |
7.97 |
|
|
|
|
|
|
Gems, R Webster, 5th edition 1994 |
|
Manganotantalite |
2.14 |
2.34 |
0.08 |
0.15 |
7.73 |
8.1 |
2.140 |
2.190 |
|
|
2.220 |
2.340 |
Tables of Gemstone Identification, Roger Dedeyne,
Ivo Quintens, 2007 |
|
Manganotantalite |
2.19 |
2.34 |
0.015 |
0.015 |
7.73 |
7.97 |
2.190 |
2.190 |
2.250 |
2.250 |
2.340 |
2.340 |
Gemmological Tables, Ulrich Henn,
2004 |
|
Manganotantalite |
2.19 |
2.34 |
0.015 |
0.015 |
7.73 |
7.97 |
|
|
|
|
|
|
http://www.gemmology.be |
|
Manganotantalite |
2.19 |
2.34 |
0.015 |
0.015 |
7.73 |
7.97 |
2.190 |
2.190 |
2.250 |
2.250 |
2.340 |
2.340 |
Joel Arem, Color Encyclopedia of Gemstones,
1987 |
|
Manganotantalite |
2.19 |
2.34 |
0.15 |
0.15 |
7.73 |
7.97 |
|
|
|
|
|
|
Gemology Tools Professional 2016 |
CAUSE OF
COLOUR
MINERAL
INCLUSIONS
LOCALITIES
|
STONE |
LOCALITIES |
REFERENCE |
|||
|
manganotantalite |
Murrua (Morrua) |
Alto Ligonha district |
Zambezia Province |
Mozambique |
The Journal of Gemmology 1979, Vol16, N°6, p363-364 |
CHEMICAL DATA
(%)
|
Stone |
Colour |
Locality |
Reference |
MgO |
FeO |
Ta2O5 |
Nb2O5 |
|
|
Manganotantalite |
dark red |
Grangal |
Afghanistan |
The Journal of Gemmology 2016, Vol 35,No2, p113 |
12.5 |
0.32 |
74.5 |
12.7 |
|
Manganotantalite |
dark red |
Grangal |
Afghanistan |
The Journal of Gemmology 2016, Vol 35,No2, p113 |
12.5 |
1.12 |
71.6 |
14.8 |