Mementoes of resolve are a reward of recognition for completing resolutions. Copper and shaped like triumphant fists, they've an inspiring lustre likely to encourage the recipient to new heights of attainment. Mementoes are hard, physical currency that can be traded, sold in a shop, or handed off to other adventurers like normal gold sovereigns.
Mementoes are primarily a currency for purchasing items from Tinker Drucker in Petra.