Incendiary gel

The Covenant utilize various types of incendiary gel as ammunition in their weaponry.

Green, radioactive incendiary gel is used in the Mgalekgolo's assault cannons and in fuel rod weaponry. The Mgalekgolo's assault cannons are able to fire the gel in mortar-like globular projectiles or in a searing stream of fire, whereas the fuel rods are compressed canisters of the material which explode upon impact.

The Type-3 firebomb, a type of native Jiralhanae grenade, uses a form of adhesive incendiary gel; a stable yet hazardous chemical mixture containing caesium. It burns at approximately twenty-two hundred degrees Celsius, and will not burn underwater.