Wildfire

Wildfire is a dangerous liquid which is created and controlled by the Alchemists' Guild in the city of King's Landing. It is a highly volatile material which can explode with tremendous force and burns with a fire that water cannot extinguish, only large quantities of sand.

Wildfire is identifiable through the distinctive green hue to its flames.

In the books
In the Song of Ice and Fire novels, the Alchemists' Guild refers to wildfire as 'the substance'. It is a very unstable material similar to napalm or Greek fire. Its use under controlled conditions was popular with some of the members of House Targaryen and some worshippers of the eastern god of fire, R'hllor, such as Thoros, who used to coat his sword with a thin layer of wildfire and then set it ablaze to scare his enemies in combat.

The alchemists refuse to divulge how wildfire is created, claiming that it is done with magical spells (a claim dismissed by others, particularly the maesters). Wildfire is stored in clay pots in bare stone cells under the Alchemists' Guildhall in King's Landing. Each cell is built under a chamber full of sand, which can be emptied into the cell below to extinguish the fire in case of accidents. Wildfire grows more volatile with age and can only be disposed of through hazardous means. Wildfire is highly combustible but can be set alight even by bright sunlight.