Ashes
From Runescape Guides & Runescape Tips
You can recieve ashes when a fire burns out. You can also get them as a 100% drop from imps and demonss because those creatures are related to fire, so Jagex allowed them to drop ashes. Ashes have virtually no value. They are not stackable and have almost no street or store price. The only real use for them is that it is needed in some quests.
