After checking out a DVD at my library I found myself so influenced by what I saw that I decided to attempt designing what I'd seen. Here are? the results.
The former has a design that is shaped like a vertically-sliced pear laid down on the sliced face. I estimate that it could hold 50 small loaves of round bread.
The latter is laid with stone mined from a local source near the Ahrn Valley. It is a stone they call "Leadstone", which has a substantial improvement over refractory stone. I gather that it might have the mineral antigorite and olivine in it which is better known as serpentine.