| Yellow Gemstones |
|---|
| Gemstone | Crystal System | Density | Hardness | Refractive index | Treatments |
 Agate |
microcrystalline | 2.66 | 6.5-7.0 | 1.544-1.553 | dying |
 Amber |
amorphous | 1.08 | 2.0-2.5 | 1.54 | heating, oiling, reconstitution |
 Beryl |
hexagonal | 2.72 | 7.5-8.9 | 1.577-1.583 | heat, radiation, fracture filling, oiling |
 Chalcedony |
microcrystalline | 2.66 | 7 | 1.544-1.553 | dying |
 Chrysoberyl |
orthorhombic | 3.72 | 8.5 | 1.746-1.755 | heat, radiation |
 Citrine |
hexagonal | 2.66 | 7.0 | 1.544-1.553 | heat |
 Diamond |
cubic | 3.52 | 10 | 2.417 | radiation, drilling, fracture filling |
 Jadeite |
microcystalline | 3.34 | 6.5-7.0 | 1.660-1.680 | dying |
 Opal |
amorphous | 2.15 | 5.0-6.5 | 1.450 | fracture filling |
 Sapphire |
hexagonal | 4.00 | 9 | 1.762-1.770 | heat, fracture filling |
 Smoky
Quartz |
hexagonal | 2.66 | 7.0 | 1.544-1.553 | none |
 Spinel |
cubic | 3.60 | 8 | 1.718 | none |
 Tiger-eye |
microcrystalline | 2.64-2.71 | 7.0 | 1.540-1.550 | none |
 Topaz |
orthorhombic | 3.53 | 8.0 | 1.619-1.627 | blue is irradiated |
 Tourmaline |
trigonal | 3.06 | 7.0-7.5 | 1.624-1.644 | heat |
 Zircon |
tetragonal | 4.00 | 6.50 | 1.810-1.815 | heat |