code/game/turfs/closed/minerals.dm 
| /turf/closed/mineral | Mineral deposits |
|---|---|
| /turf/closed/mineral/snowmountain/do_not_chasm | Near exact same subtype as parent, just used in ruins to prevent other ruins/chasms from spawning on top of it. |
| /turf/closed/mineral/volcanic/lava_land_surface/biome_replace | Rock type which replaces itself with whichever rock would've been generated by the biome underneath |
| /turf/closed/mineral/volcanic/lava_land_surface/do_not_chasm | A turf that can't we can't build openspace chasms on or spawn ruins in. |
| /turf/closed/mineral/ash_rock | Wall piece |
| /turf/closed/mineral/snowmountain/icemoon/unscrapeable | This snowy mountain will never be scraped away for any reason what so ever. |