RuneScape Classic Wiki
RuneScape Classic Wiki
The main RuneScape Wiki has an article on: Iron ore certificate

An Iron ore certificate is a certificate that is mainly obtained by exchanging five iron ores with Giles at Draynor Village market or Jinno at Zanaris. 30 iron ore certificates may also be obtained from the Crystal chest in Taverley.

Iron ore certificates are stackable, and each one can be exchanged back for five iron ores by talking to Giles or Jinno.

Because iron ores are not stackable and players can only trade twelve items per trade screen, they are often exchanged for certificates so that they can be traded easier and faster.

Dropped by

Monster Combat level Quantity Rarity
King Black Dragon 245 20 4Rare