Stone

Stone is a crafting material in Survival 303 with a large number of uses.
Stone can be used to make buildings by crafting 2 Boulder ​​​​into one Stone Wall, which is used for a large number of mid-game to late-game buildings.
It can also be used to create tools, by making two stone into Cut Stone, where it can then be turned into an axe or a pickaxe.  Making two Cut Stone into a tool creates Flint, an early-game firestarter.