While the Voice is active in the district, corrupted ores may be obtained from mining any ore, including harmonised rocks; higher level ores yield corrupted ore at higher rates. Corrupted ores may be obtained from the crystal chest in the Iorwerth Clan's district. With level 89 Smithing, corrupted ores can be used at furnaces, awarding Smithing experience. If using corrupted ores while the Voice is active in the district, swamp tar is produced at a rate of roughly 25%. Players are able to use temporary skill boosts to dispose of corrupted ores at furnaces.