Hello! Yes, the tunnels in the mountains to the northwest could have junior frostwurms that haven't yet migrated further north. They are not dangerous and quite small. These crystals are not harvested since their properties are too weak to be effective.

This means Thancred could gather a few without issue since Thorne would not have any real use for them. The healing properties of the crystals would not be very strong, though it could heal a minor wound. Its hallucinogenic effect is also more mild but exposure could cause minor shared visions with another person. You're free to determine what the hallucination might look like! They can be amusing or darker.

The hallucinatory effect would only last a few minutes before fading.