| Limit | |
| Purity(metal oxide basis): | 99.1% min. |
| Assay as Nd(NO3)3&183;6H2O: | 48 - 52% |
| Specific Gravity at 20°C: | 1.34 - 1.36 |
| Praseodymium Oxide: | 0.7% max. |
| Iron Oxide: | 10 ppm max. |
| Calcium Oxide: | 10 ppm max. |
| Sodium Oxide: | 10 ppm max. |
| Appearance: | purple solution |