Which gas is best for granulation

When it comes to doing anything in jewelry the cleaner the gas burns
(translated less carbonizing of surfaces) the better. Use propane or
natural gas with a large “rosebud” tip. Propane burns very cleanly and is
hotter than natural gas. The draw back is that it is more potentially
dangerous to use because it is a compressed gas (bottled) and for some
delicate soldering operations it could turn your beautiful filigree
pendant into a ball of metal unless you are very careful/experienced using

Good luck, Mike Campbell