The emerald lantern is a lightsource which is used during the Lunar Diplomacy quest. It is created by using the emerald lens with a bullseye lantern (empty). It must be lit with a tinderbox to create the emerald lantern (lit). Level 49 Firemaking is required to light it. It is similar to the sapphire lantern, but unlike the sapphire lantern it is not made using a cut gem. If lost, the emerald lens can be recovered by speaking to the Cabin Boy who can be found slightly north-west of the Lunar Isle bank.
This lantern cannot swap the emerald lens with bullseye lantern, as the sapphire lantern can.