| Species |
Formula |
Mohs |
Density |
RI |
Dispersion |
| Alexandrite |
Al2BeO4
|
8.5 |
3.72 |
1.75 |
0.015 |
| BGO-12 (White Bismuth Germanate) |
Bi4Ge3O12
|
4.5 |
7.13 |
2.09 |
0.102 |
| BGO-20 (Orange Bismuth Germanate) |
Bi12GeO20
|
4.5 |
9.22 |
2.57 |
0.221 |
| GAGG (Gadolinium Aluminum Gallium Garnet) |
Roughly Gd3Al2Ga3O12
|
8 |
6.6 |
1.9 |
~0.033 |
| GGG (Gadolinium Gallium Garnet) |
Gd5Ga3O12
|
6.5-7.5 |
7.08 |
1.97 |
0.045 |
| LaB6 (Lanthanum Hexaboride) |
LaB6
|
8 - 9 (?) |
4.72 |
opaque |
opaque, >2 |
| Lithium Niobate |
LiNbO3
|
5 |
4.65 |
2.3 |
0.125 |
| Lithium Tantalate |
LiTaO3
|
5.75 |
7.45 |
2.18 |
0.075 |
| LuAG (Lutetium Aluminum Garnet) |
Lu3Al5O12
|
8 |
6.7 |
1.9 |
0.025 |
| LYSO (Lutetium-Yttrium Oxyorthosilicate) |
Between Lu2SiO5 and Y2SiO5
|
5.8 |
4.4 (YSO) to 7.4 (LSO) |
~1.8 |
~0.03 |
| Moissanite |
SiC |
9.25 |
3.22 |
2.65 |
0.104 |
| Rutile |
TiO2
|
6.5 |
4.25 |
2.61 |
up to 0.330! |
| Sapphire/Ruby |
Al2O3
|
9 |
3.98 |
1.76 |
0.018 |
| Strontium Titanate |
SrTiO3
|
5.5 |
5.1 |
2.4 |
0.19 |
| TGG (Terbium Gallium Garnet) |
Tb3Ga5O12
|
8 |
7.13 |
1.95 |
~0.045 |
| YAG (Yttrium Aluminum Garnet) |
Y3Al5O12
|
8.5 |
4.5 |
1.8 |
0.028 |
| Zinc Sphalerite |
ZnS |
4 |
4.05 |
2.36 |
0.163 |
