I can tell u how to get all the gems :)
1. Between the nursery and Ashtail (aka at the dip) If you slip in the little water thing a white pearl gem will appear
2.Click Alyssa (The owl in thw tree) after Amberclaw tells you who Alyssa is click the blue gem in the tree and Alyssa will give you the gem
3.Go to the beach and click the yellow gem in the water
4.Two ways to do this one. If you are an apprentice go to the herbal Grounds and talk to Nightpaw, she will tell you about a gem she found and left in the apprentice den for u. If you are a warrior go up to the overview and talk to Nightwhisper, she will tell u about the gem ect go get it at the apprentice den.
5. U have to be leader for this. After u become leader talk with Liontail, he will give u his gem,
(I can tell u how to become leader : Once a warrior talk with Moonheart, she will tell u about mosskit, go to the warrior den and get the moss on one of the beds, go to the beach and place the moss on the X and then wait until Mosskit comes to the beach. Go with her to Bramblestar.
He will make u leader if u helped the clan like helping the medicine cat get a new den.
(How to help the medicine cat: Talk to her as a warrior, she will tell you about her wanting a new den. Go fight off the badger and then go tell her about the new empty place)
//Hoped this helped u and other players