Best places to get each gem type on abberation

Green: all around fertile lake there’s big clusters

Blue: the pathway from the mushroom forest to the bioluminescent swamp in between the two water falls(wear a hazmat suit or bring aquatic mushrooms for the freezing mushrooms)

Red: halls of the reaper queen in the south west of the map (reaper queens are very common and extremely dangerous if unprepared)

Bring a crab and anky for green and blue gems there will be very little risk other than basilisks, drakes and megalosaurus

For red gems a small group is recommended due to the very dangerous area however solo on a drake with a pick is easily doable if you are alert and know what you are doing