Well, go to Violet and she will say she found gems lying on the street and gave them to Mayor Hopkins. So, go to Mayor Hopkins and he'll say he needs proof. So, go to your assistan with the green hair and he will give you a picture of Lindsay and her gems and Mayor Hopkins will five you the gems. Then, go to Lindsay and give them to her. She will give you a diamond. Then, talk to her again and she will give you an Amythest or something like that. Hope this helps! :)