I’m thinking there could be a global counter when on the planet or a counter above each volcano that tells you when the planets are about to erupt and people run for the gleam.
They could shoot out in small meteor fashion around in many directions. And if there are multiple volcanos on the planet that are set to erupt at various times then people can run from volcano to volcano collecting rare gleam.
Or maybe the volcano has red cracks that glow when it’s about to blow. And the wind audio picks up. Maybe a new music snippet that gets your blood pumping for GLEAAAAAAAAAM!!!