A florb (‘fluid orb’) is a throwable item that contains a fluid.
An empty florb can be filled with a bucket worth of fluid using a fluid transposer or similar. Florbs can only hold fluids that can be placed as blocks using buckets.
A florb cannot hold hot fluids like lava. These fluids can only be put into magmatic florbs.
A filled florb can be thrown by using it. On impact, it releases the fluid it holds into the world.
Florbs that contain fluids that are lighter than air, like energized glowstone and zephyrean aerotheum, can be thrown further.