This a list of the locations of the gems in Cavern Catastrophe.
After the tutorial of hitting crystals to make rocks fall, there will be two tunnels. Take the one that has the Skull and Crossbones gate in front of it. When heading through the tunnel the player will find the gem right in the middle of the path.
In one area there will be two paths both with Nitro on it. Take the right path and soon the player will roll up a ramp over toxic waste were a Gem is directly in the player's path.
In one area, the player must carefully bounce from platform to platform using bounce crates. The last one will have a Clear Gem on it.
When the player is going down a series of waterwheels there will be a trap door and another waterwheel beside it. The player must roll onto the other waterwheel. When the player is on the waterwheel, they must roll onto another trap door and they must drop through it onto another. When that one opens, the player will fall onto a platform with the Gem.
After the cutscene where Cortex says "Throw me over there", there will be a platform with a gem and a few Rats. You must toss Cortex over to the platform so he can collect the gem OR you can jump there yourself.
During the Drill Chase sequence, there is an easy gem on a platform just before the chase is finished.