how to cause Griffons to spawn?Follow

I am working on cultural symbols. Need Lambent Stones to make Expert's Water of the Skeptic. Which mobs in East and North Karana need to be done away with to get more griffons?
I am always finding griffawns, but they don't drop the stones.

Or, alternatively, how do you spawn sand giants or hill giants in their zones? I don't bother with the Rathe Mountains hill giants because they are always camped.

Your better off killing the hill giants for lambent stones.

I was having the same problem getting the stones. My buddy needs them for the armor quest as well but the stupid HG's are always dead or dying so sadly the best way to get them is to purchase them off of the pally vendor for 50 plat with my monks 89 charisma. The little pukes at level 70 would not sell them to me to i bought them for the whole 50 plat. Which is a lot but still going to make money if you are able to use/sell the augs and armor. I still can't believe how over hunted they are by level 70's for the cash it boggles my mind.