|
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 |
|
Grandidierite |
1,568 |
1,67 |
0,035 |
0,05 |
2,88 |
2,92 |
light bluish green to
intense bluish green |
Madagascar |
6 samples are rough materials weighing from
0.41-1.24 cts |
|
|
|
|
|
|
|
inert |
inert |
https://www.git.or.th
2017 30 Mar |
|
Grandidierite |
1,579 |
1,62 |
0,041 |
0,041 |
2,91 |
2,91 |
greyish blue-green |
Madagascar |
|
|
|
|
|
|
|
Faint absorption line in
the blue spectrum around 470-490 nm |
|
|
Gems & Gemology 2015
Winter, p449 |
|
Grandidierite |
1,58 |
1,62 |
0,04 |
0,04 |
2,94 |
2,94 |
greyish blue-green |
|
1.79ct |
1,580 |
1,580 |
1,605 |
1,605 |
1,620 |
1,620 |
|
|
|
ACAM lab 4610 |
|
Grandidierite |
1,58 |
1,63 |
0,04 |
0,04 |
3,04 |
3,04 |
greenish blue |
Madagascar |
0.31ct |
|
|
|
|
|
|
faint line / absorption
at around 470 nm |
|
|
http://gtljaipur.info/ProjectUpload/labDownLoad/LIC%2074%20_June2017.pdf |
|
Grandidierite |
1,58 |
1,62 |
0,04 |
0,04 |
|
|
green |
|
1.43ct, repaired |
|
|
|
|
|
|
|
|
|
Gems & Gemology 2022
Spring, p53 |
|
Grandidierite |
1,583 |
1,622 |
0,039 |
0,039 |
2,96 |
2,96 |
greenish blue |
Sri Lanka |
1 stone, transparent |
1,583 |
1,583 |
1,620 |
1,620 |
1,622 |
1,622 |
line at 479nm |
inert |
inert |
Gems & Gemology 2003
spring, p32-37 |
|
Grandidierite |
1,583 |
1,622 |
0,039 |
0,039 |
2,85 |
2,85 |
slatey blue, translucent |
|
|
|
|
|
|
|
|
|
|
|
The Journal of Gemmology
1977 N°7, p357-358 |
|
Grandidierite |
1,585 |
1,62 |
0,035 |
0,035 |
2,96 |
2,96 |
greenish blue |
Sri Lanka |
0.37ct |
|
|
|
|
|
|
line at 482nm |
inert |
inert |
GIA Gem Database 35629 |
|
Grandidierite |
1,59 |
1,639 |
0,033 |
0,033 |
3 |
3 |
blue-green |
Andrahomana, Madagascar |
|
1,590 |
1,590 |
1,618 |
1,618 |
1,623 |
1,623 |
|
|
|
Gemmologie, Zeitschrift
der Deutschen Gemmologischen Gesellschaft 2000 Sep, p121 |
|
Grandidierite |
|
|
|
|
2,99 |
3,03 |
bluish green to greenish
blue |
Tranomaro area,
Departementa Amboasary, Anosy, Toliara Province, Madagascar |
|
|
|
|
|
|
|
|
inert |
inert |
Gems & Gemology 2016
Fall, p 266-275 |
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 |
|
Grandidierite |
1.577 |
1.625 |
0.036 |
0.042 |
2.9 |
3 |
|
|
|
|
|
|
Gemmo.eu
|
|
Grandidierite |
1.583 |
1.639 |
0.039 |
0.039 |
2.85 |
3 |
1.583 |
1.602 |
1.618 |
1.636 |
1.622 |
1.639 |
Joel Arem, Color
Encyclopedia of Gemstones, 1987 |
|
Grandidierite |
1.583 |
1.639 |
0.037 |
0.039 |
2.85 |
3 |
1.583 |
1.602 |
|
|
1.622 |
1.639 |
Gemme, Dati per l'identificazione, P. De
Stefano et al, 1993 |
|
Grandidierite |
1.583 |
1.6 |
0.037 |
0.039 |
2.85 |
3 |
1.583 |
1.602 |
1.620 |
1.636 |
1.622 |
1.600 |
Gemmological Tables, Ulrich Henn,
2004 |
|
Grandidierite |
1.583 |
1.639 |
0.039 |
0.039 |
2.85 |
3 |
|
|
|
|
|
|
http://www.gemmology.be |
|
Grandidierite |
1.583 |
1.639 |
0.039 |
0.039 |
2.85 |
3 |
1.583 |
1.602 |
1.618 |
1.636 |
1.622 |
1.639 |
http://www.geminterest.com |
|
Grandidierite |
1.583 |
1.629 |
0.039 |
0.039 |
2.85 |
3 |
1.583 |
1.602 |
1.618 |
1.636 |
1.622 |
1.629 |
Tables of
Gemstone Identification, Roger Dedeyne, Ivo Quintens, 2007 |
|
Grandidierite |
1.583 |
1.639 |
0.039 |
0.039 |
2.85 |
3 |
|
|
|
|
|
|
Gemology Tools Professional 2010 |
|
Grandidierite |
1.602 |
1.639 |
0.037 |
0.037 |
3 |
3 |
|
|
|
|
|
|
Bestimmungstabellen für Edelsteine,
Birgit Günther, 1981 |
|
Grandidierite |
1.602 |
1.639 |
0.037 |
0.039 |
3 |
3 |
|
|
|
|
|
|
Tabellen zur Edelstein-Bestimmung,
Pschichholz FGA, 1975 |
|
Grandidierite |
1.602 |
1.639 |
0.037 |
0.037 |
3 |
3 |
|
|
|
|
|
|
Gems, R Webster,
5th edition 1994 |
CAUSE OF
COLOUR
|
Stone |
Colour |
Cause
of colour |
Reference |
|
Grandidierite |
blue |
Fe²+ ion and its
interaction with Fe³+ |
http://minerals.caltech.edu |
MINERAL
INCLUSIONS
LOCALITIES
|
STONE |
LOCALITIES |
REFERENCE |
|||
|
Grandidierite |
Cap Andrahomana, Departementa Ranopiso |
Anosy (Fort Dauphin Region) |
Toliara (Tuléar) Province |
Madagascar |
Michael O'Donoghue, Gems:
Their Sources, Descriptions and Identification (2006), 873pp |
|
Grandidierite |
Tranomaro area, Departementa Amboasary |
Anosy (Fort Dauphin Region) |
Toliara (Tuléar) Province |
Madagascar |
Gems & Gemology 2016 Fall p266-275 |
CHEMICAL DATA
|
Stone |
Colour |
Locality |
Reference |
SiO2 |
Al2O3 |
MnO |
MgO |
FeO |
TiO2 |
CaO |
Cr2O3 |
Fe2O3 |
B2O3 |
|
|
Grandidierite |
|
|
Sri Lanka |
Gems & Gemology 2003 Spring p34 |
20.2 |
52.64 |
0.03 |
12.85 |
1.31 |
0.01 |
0.01 |
0.07 |
0.01 |
11.91 |
|
Grandidierite |
|
|
Madagascar |
Gems & Gemology 2015 Winter, p450 |
16.41 |
53.89 |
0.01 |
17.01 |
0.3 |
|
|
0.01 |
|
12.33 |
|
Grandidierite |
|
southern Madagascar |
Madagascar |
Gems & Gemology 2016 Fall, p 272 |
20.25 |
53.17 |
|
14.28 |
0.52 |
|
|
|
|
10.38 |