elements
Sulphur
S
- Also known as
- brimstonesulfur
- Crystal system
- orthorhombic
- Hardness
- 1.5–2.5 on the Mohs scale
- Lustre
- resinous
- Colour
- Bright yellow
- Where it forms
- Around volcanic vents and hot springs, where hydrogen sulfide oxidises, and in salt dome cap rock where bacteria reduced sulfates.
- Chiefly from
- SicilyJava, IndonesiaBoliviaLouisiana and Texas, United States
Why it is that colour
The element itself. Nothing else in mineralogy is quite that yellow.
Safety
Elemental sulfur is low in toxicity and is used in agriculture and dermatology. It burns readily with a blue flame, producing sulfur dioxide, which is acutely irritating to the lungs — so do not heat it. Specimens are fragile and crack from the warmth of a hand.
Where it comes from
Almost all sulfur now comes as a by-product of removing sulfur compounds from oil and gas, not from mining. Sicilian mining, which used child labour extensively into the twentieth century, ended long ago.
Historical use
Gunpowder is saltpetre, charcoal and sulfur. Sulfuric acid, made from it, is produced in greater quantity than any other industrial chemical, and its consumption has been used as a rough index of a country’s industrial output.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
What is attributed to it, and since when
Brimstone, and the association with fire, purification and the infernal is as old as written record — Homer describes burning sulfur to purify a house. In alchemy sulfur is one of the three principles, standing for the combustible, active, masculine aspect of matter, paired with mercury and salt.
Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.
Worth knowing
The IMA's approved spelling is Sulphur, with the British ph, which is an odd survival given that chemistry standardised on sulfur decades ago. Mineral names are governed by their own body and their own precedents, and this is one of the places where the two conventions have simply not converged.
The Kawah Ijen mine in Java is worth knowing about, because it is still worked by hand. Miners carry baskets of solid sulfur weighing seventy to ninety kilogrammes up out of a volcanic crater, through sulfur dioxide fumes, several times a day. It is among the most photographed and least improved working conditions in modern mining.
Identity checked against IMA-CNMNC master list, June 2025.