When a character finds a piece of metal or precious stone, he/she must make a dice roll using his/her Smith (including relevant specialisms) or Mining (including relevant specialisms) + PE to recognise it.
If the dice roll is successful, the referee should tell the player what the metal or precious stone is and describe its properties. If the dice roll fails, the referee should simply describe to the player what the character sees.
The difficulty depends on how common the metal or stone is:
| Rarity | Difficulty value |
| Common (e.g. iron, steel, diamond) | 2 |
| Uncommon (e.g. aluminium, fire opal) | 6 |
| Rare (e.g. mithril, meteoritic iron) | 10 |
| Very rare (e.g. a metal or stone the referee has invented) | 14 |