This is not required for students of EPS2
| GEMSTONE | WEIGHT | RADIONUCLIDES | DIRECT READINGS |
| (ct.) | PRESENT | (cpm) | |
| Green zircon | 2.2 | U-238 | 300 |
| Green zircon | 3.7 | U-238 | 200 |
| Ekanite | 3.9 | U-238 | 5500 |
| Th-232 | |||
| Blue topaz | 4.6 | Sc-46 | 75 |
| (neutron irradiated) | |||
| Blue topaz | 4.7 | Ta-182 | 110 |
| (neutron irradiated) |