I just rerolled, about the best $10 I ever spent. My second rental was good, but the first, I messed it up by taking the trench biome. Ruined about 2/3’s of the planet for both gems and making it a deathtrap in spots. I wanted a good emerald planet.
So tried again… not only double the emerald, but I got real cute with selecting the biomes for gleam… well, go check out my posts here, rather than post them again…
My second rental was good, but the first, I messed it up by taking the trench biome. Ruined about 2/3’s of the planet for both gems and making it a deathtrap in spots. 
I wanted a good emerald planet.