Imo, glass & ceramic are best for bowls, being inert.
There was a brand of tobacco pipes back in the 60's called The Pipe, and the bowl was lined with a ceramic material that was used on the nose cone of rockets to prevent them from burning up.
Wood bowls are good IF they have been properly cured & prepared.
Worst are alum. and tin foil bowls. They produce toxic fumes when heated. I dislike any type of metal bowl since they get too hot.
I once found a HUGE burl of Manzanita wood. The burl is where the trunk meet the roots, just underground.
Most of these burls are full of cracks and are good for little besides firewood. But this burl was from a tree that had been buried who knows how many years earlier by a mudslide. That allowed it to dry out very slowly, preventing cracks.
Manzanita is a very dense wood (like briar, which most tobacco pipes are made from). It also has a very beautiful grain and color.
I turned this over to a friend of mine who is a master carver. $300.00 worth of saw blades later, he presented me with: 15 small dope pipes, 2 matched tobacco pipes, and a nearly 2' long "peace pipe", in 2 sections.
The dope pipes were real works of art and I wish I had pics. Some were shaped like a coffin, some like snakes, one was like a sort of revolver with 6 one-hit bowls that rotated, another had 2 bowls and a slide where you could choose either bowl or both at the same time.