Hey @james,
Molav here with another random suggestion. 
What if you make a new exo type with volcanos that spew random gleam colors out of it?
Like this, so that rare gleam has a chance to be in the universe any time an exo with volcanos show up???
I think this would be amazing!!!
And we just stand there with a loot stick 
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!!!