Heavy Lamp is a mod which adds the titular block Heavy Lamp, a paper lamp which is affected by gravity.
This block is useful for (manual) quarry mining (especially during the night).
You can place it in the quarry, mine underneath it as needed, and the lamp will come with you further down the mine, no need to constantly place torches on the walls.
I'm not sure if the lamp has any other utility other than this and decoration.
