The Idunn Apple is a golden, luminescent fruit with a smooth, slightly textured surface that glows faintly, symbolizing its divine nature. Its shape is perfectly spherical with a subtle organic irregularity, featuring a small stem at the top and a delicate leaf attached. The apple's skin has a polished, metallic sheen with intricate, faintly visible Norse runes etched into its surface, hinting at its magical properties.