No. Volcanic activity does often produce a fair amount of sulfur but it's very impure as is the sulfur from petroleum byproducts. We built a huge steel tank for molten sulfur at a refinery and one day on the job near the new tank I found some solidified hunks of sulfur I took out with me. It's not real pure but pure enough to burn. The globules of sulfur near the dead sea at the sites of Sodom and Gomorra are nearly pure and very light colored. They are found incased in sulfur ash which proves they were burning when the deposits were made. I've worked on tank repair where sulfur was deposited on rafters near where I had to cut loose the old steel roofing. Of course the stuff was constantly catching fire and dripping sulfur ash and molten sulfur on me. The stuff is hellishly hot. I still have scars from that job.