This article describes content that exists in the game's data, but is not obtainable by normal means.
Grounds were items that could be dug up with a shovel from floor tiles in the world. The effectiveness is based on the player's digging damage stat.
As of 0.7.3-3c7e, ground items are no longer obtainable with the merging of wall and ground items - digging up their respective tile drops the proper block instead.
0.7.3-3c7e: Made unobtainable with the merge of wall and floor placement. Any existing ground items in chests and inventories still remain after this update.
0.3.12-8ddf: Added a digging damage stat to shovels that impacts how many uses it takes to dig up ground. Health of ground has been rebalanced around the digging damage of shovels so that higher tier shovels are more effective against lower tier ground and lower tier shovels are less effective against higher tier ground.