Gravel

Additional loot drop in addition to existing Piglin Trade.

Silverfish inhabit a block until provoked to leave. The block normally disappears from existence but it should be in some kind of damaged state given a creature tunnelled through it.

Added gravel as ground up remains of the stone blocks the Silverfish leave behind.
Gravel will drop from a block regardless of if a player broke it manually, or the Silverfish leaves it itself. Designed to be farmable.