"I use river rocks for my hot stone massage. I have heard some folks say that river rocks might have faults that will cause the stones to explode from steam build up, but this is not the case. I do NOT heat the rocks past the boiling point anyway.
I did ask permission from the universal energies for the use of the stones.
I just went to the river and found a good set of different sizes and types of stone.
Flint holds heat the best but the quartz will heat up nicely as well.
If you want bassalt, you can always go to Iceland and get a set from the volcanic lakes there. "I saw it in the website Pubspa.com.If u want to know more ,u may google it.It's FREE to be a member!