not really. I think I got this randomly from loot containers

According to rumors in the POI's (riddle ruins) or as a quest reward. I've quested all the way through Barnsdale Region and Sherwood Forest Region +60% POI's and haven't found any yet.

@@JustOnlyGameplayand how can i pass the river to the meteorite mine? it's impossible. all bridges are elevated

I'm not there yet. But I read that you can get there with a questline

@@JustOnlyGameplay You get there after you conquer the Sandal Castle. You have to follow the main quests for that. I am releasing a gameplay and walkthrough in the next days with keyframes for all quests. So you can check it in couple of days (:

You can buy amber, obsidian, topaz and diamond from a vendor near a well in the center of Nottingham. It's expensive, and maybe you have to achieve a main mission, not shure about that...