Taiyonite

The aarakocra of Sun Crest will often use semi-precious gems, a mineral known as taiyonite, as a trading currency between their towns and tribes. It is a gem that essentially only the aarakocra can mine, as its veins can only be found at the tops of the mountains of Sun Crest, inaccessible to anyone except those able to fly. It is also accepted by merchants in The Peninsula, Verdain, parts of the Commonwealth, and Gold Plains.