From left to right, I think these are the following gemstones:
- Amethyst
- Dyed Howlite (a.k.a. Turquenite) (But, you can also get Turquoise in similar pattern.)
- Chalcedony (I don’t know if this can be amber. Needs testing.)
- Natural Glass (I also think it as Obsidian but it will require testing to confirm it.)