Sulphur

Sulphur is an item dropped by Warped terrorbirds and Warped tortoises. It can also be picked up to the north of the Poison Waste. It can be ground using a pestle and mortar to make Ground sulphur.

Trivia

 * Sulphur was made untradable in the 20 November 2007 update because some scammers used to sell it for a high price, claiming it was rare. Some players believe this restriction should now be lifted, as the subsequent additions of the Grand Exchange, Trading limits between players makes the scam unlikely now.