|
INVESTIGATIONS
|
Stone |
RI min |
RI max |
Dens min |
Dens max |
Colour |
Location |
Info |
Spectrum |
UVS |
UVL |
Reference |
|
Almandine-spessartine |
1.8 |
1.8 |
4.17 |
4.17 |
orange-red |
Lindi, Tanzania |
1.35ct |
weak absorption lines at 480 and 520 nm, stronger lines at 460, 505, and
565 nm, and general absorption to 440 nm. |
inert |
inert |
Gems & Gemology 2008 Summer, p165 |
|
Almandine-spessartine |
1.81 |
1.81 |
4.19 |
4.19 |
|
|
2.52ct |
|
|
|
Gems & Gemology 2011 Winter, p274 |
|
Almandine-spessartine |
1.81 |
1.81 |
4.22 |
4.22 |
|
|
6.78ct, composition: Sps63Alm37 |
|
|
|
Gems & Gemology 2011 Winter, p274 |
|
Almandine-spessartine |
1.812 |
1.812 |
4.26 |
4.26 |
|
|
1.62ct, composition: Sps53Alm47 |
|
|
|
Gems & Gemology 2011 Winter, p274 |
|
Almandine-spessartine |
|
|
4.13 |
4.13 |
deep brownish red |
Clearwater County, Idaho, USA |
11.06ct |
a strong 432.0-nm band + almandine spectrum |
|
|
Gems & Gemology 1986 Fall, p 187 |
|
Almandine-spessartine |
|
|
4.21 |
4.21 |
|
Congo |
0.85ct, composition: 46.6%Spes-40.5%Alm-7.4%Pyr-5%Gros |
|
|
|
The Journal of Gemmology 2019 Vol 36, N°5, p408 |
|
Almandine-spessartine |
|
|
4.25 |
4.25 |
very dark orangy red |
Czech Republic |
18.34ct |
band at 565-585nm |
inert |
inert |
GIA Gem Database 33197 |
|
Almandine-spessartine |
|
|
4.33 |
4.33 |
very dark reddish orange |
Orissa, India |
12.86ct |
band at 495-515, 530-535, 570-575nm, line at 465nm |
inert |
inert |
GIA Gem Database 33222 |
TABLES
|
Stone |
RI
min |
RI
max |
Dens
min |
Dens
max |
Reference |
|
Almandine-spessartine |
1.808 |
1.822 |
3.96 |
4.3 |
Gemmo.eu 2013 |
|
Almandine-spessartine |
1.81 |
1.82 |
4.12 |
4.25 |
http://www.gemmology.be |
|
Almandine-spessartine |
1.81 |
1.82 |
4.14 |
4.31 |
http://www.geminterest.com |
|
Almandine-spessartine |
1.81 |
1.82 |
4.12 |
4.25 |
Tables of Gemstone Identification, Roger Dedeyne,
Ivo Quintens, 2007 |
CAUSE OF
COLOUR
MINERAL INCLUSIONS
|
Inclusion |
Stone |
Reference |
|
apatite |
Almandine-spessartine |
http://www.geminterest.com/ |
|
rutile |
Almandine-spessartine |
E.J. Gübelin and J.I. Koivula, Photoatlas of
inclusions in Gemstones, volume 2 (2005) |
LOCALITIES
|
STONE |
LOCALITIES |
REFERENCE |
|||
|
almandine-spessartine |
Star garnet locality, Ambatondrazaka Department |
Alaotra-Mangoro Region |
Toamasina (Tamatave) Province |
Madagascar |
The journal of Gemmology, 2002, Vol28, N°1, p13-23 |
CHEMICAL DATA
|
Stone |
Colour |
Locality |
Reference |
SiO2 |
Al2O3 |
MnO |
MgO |
FeO |
TiO2 |
CaO |
Na2O |
Cr2O3 |
V2O3 |
Fe2O3 |
|
|
Almandine-spessartine |
reddish to purplish brown, opaque, star |
Ambatondrazaka |
Madagascar |
The Journal of Gemmology 2002, Vol 28, N°1, p19 |
36.32 |
20.93 |
8.96 |
20 |
31.71 |
0.04 |
0.47 |
|
0.01 |
0.02 |
|
|
Almandine-spessartine |
reddish to purplish brown, opaque, star |
Ambatondrazaka |
Madagascar |
The Journal of Gemmology 2002, Vol 28, N°1, p19 |
36.28 |
20.87 |
8.6 |
1.9 |
32.5 |
0.06 |
0.36 |
|
0.01 |
0.01 |
|
|
Almandine-spessartine |
reddish to purplish brown, opaque, star |
Ambatondrazaka |
Madagascar |
The Journal of Gemmology 2002, Vol 28, N°1, p19 |
36.5 |
20.9 |
8.02 |
2.17 |
32.48 |
0.14 |
0.6 |
|
0.02 |
0.01 |
|
|
Almandine-spessartine |
orange-red |
|
Sri Lanka |
The Journal of Gemmology
2007,30,5/6,307-319 |
35.47 |
20.63 |
16.75 |
0.44 |
24.08 |
0.03 |
0.26 |
0.06 |
0.01 |
|
2.14 |