Eggshell

Eggshell is an item produced when a bird egg breaks. It can be used as fertilizer to grow crops.

Mob Loot
Throwing any of the bird eggs will occasionally produce eggshell upon collision with a block.

Analysis
When analysing mystery eggs in an egg analyser, 2-3 eggshell can be obtained if the analysis fails. There is a 1 in 3 chance of this happening.

Fertilizer
Just like bone meal, eggshell can be used on various plants to increase their growth stage.