One of the symbols for sulphur in alchemy is also known as the Satanic cross or Leviathan cross. It consists of the symbol for infinity topped with a double cross.
In alchemy, sulphur is the active, male principle that acts on mercury to create all other metals and is a "manifestation of the will of heaven."1 In the Bible, sulphur (brimstone) is connected to guilt and punishment, most famously at Sodom.
This symbol of sulphur was used to illustrate the Nine Satanic Statements in The Satanic Bible by Anton LaVey. According to a Church of Satan website, LaVey "used it as a spooky decoration and it has no other significance despite some hilarious interpretations by evangelical Christians."2