TABLE III
Refractive Indices of Gem-Stones[8]
| Opal |
1·454 |
| Moonstone |
1·53 |
1·54 |
| Iolite |
1·543 |
1·551 |
| Quartz |
1·544 |
1·553 |
| Beryllonite |
1·553 |
1·565 |
| Beryl |
1·578 |
1·585 |
| Turquoise |
1·61 |
1·65 |
| Topaz |
1·618 |
1·627 |
| Andalusite |
1·632 |
1·643 |
| Tourmaline |
1·626 |
1·651 |
| Apatite |
1·642 |
1·646 |
| Phenakite |
1·652 |
1·667 |
| Euclase |
1·651 |
1·670 |
| Spodumene |
1·660 |
1·675 |
| Enstatite |
1·665 |
1·674 |
| Peridot |
1·659 |
1·697 |
| Axinite |
1·674 |
1·684 |
| Diopside |
1·685 |
1·705 |
| Idocrase |
1·714 |
1·719 |
| Spinel |
1·726 |
| Kyanite |
1·72 |
1·73 |
| Epidote |
1·735 |
1·766 |
| Garnet (Hessonite) |
1·745 |
| Chrysoberyl |
1·746 |
1·753 |
| Garnet (Pyrope) |
1·755 |
| Benitoite |
1·757 |
1·804 |
| Corundum |
1·761 |
1·770 |
| Garnet (Almandine) |
1·790 |
| Zircon (a) |
1·815 |
| Garnet (Demantoid) |
1·885 |
| Sphene |
1·901 |
1·985 |
| Zircon (b) |
1·927 |
1·980 |
| Diamond |
2·417 |