This symbol is popularly referred to as a Leviathan Cross. It was named as such by Howard Stanton Levey (1930–1997), who changed his name to the more exotic-sounding Anton Szandor LaVey, dabbled in the occult and adopted the symbol as an emblem of his Church of Satan in the 60s. A satanic cross is a curious notion because unlike Jesus, Satan was never crucified; rather he rejected the Grace of God.
Satanists may curse us if they wish, but since there is no monopoly on cross shapes, on this page we are reclaiming any satanic association of the symbol for its Christian interpretation.
also called a Leviathan Cross
Brimstone is the lemon coloured stone found at the brim of volcanoes and hot springs. This chemical is now more usually known by its Latin name sulfur, and the term 'brimstone' tends to be reserved for references in ancient texts such as the Bible.
It's also in the Bible that we find references to a great sea monster called Leviathan. (In modern Hebrew the word translates to "whale". They're big, but don't really fit the profile sought by Satanists.)
Alchemical symbol for sulfur
Alchemists have used different symbols for sulfur, including the upward-pointing triangle surmounting a cross. The triangle in alchemy symbolises fire, and the cross symbolises earth.
There's an interesting similarity with Chinese and Japanese characters where 'fire' is shown as and 'earth' is represented as . Similarly with the double-barred cross of the brimstone symbol, the Sino-Japanese character for 'out' is , which may be an old pictogram for an erupting volcano.
The chemical symbol is simply "S".
God made sulphur, and it happens to be an element that's essential for life, which must be a disappointing fact for Satanists.
As you know, Christianity uses many different symbols. For example, "S" (the symbol for sulphur) is often used to represent Salvation. The cross of course also symbolises Salvation, and the triangle symbolises the divinity of Christ.
Further, the cross combined with the infinity symbol symbolises everlasting life.
Even the downwards-pointing pentagram has been used by Christianity for centuries.
So we're sorry, members of the Church of Satan, but it looks like your founder copied symbols that mean the opposite to your beliefs.
Traditionally spelt 'sulphur' in British English, but universally as 'sulfur' in chemistry.
The character symbolises a small mountain on top of a larger mountain, representing the subaerial growth due to volcanic activity.
See also Pagan Symbols used in Christianity