The Shovel is an item which is required to find Sand. When bound, it starts collecting automatically over time.

Upgrading a blue orb allows the shovel to automatically collect fishing bait slowly over time. Upgrading it with gems also affects its chance.

Gems Sand Chance Per Second
Empty 1/1000
Sapphire 1/800
Emerald 1/600
Ruby 1/400
Diamond 1/200