Stone is a basic building material for buildings and for crafting recipies.
They are obtained from Gatherers (although slow) or especially from Quarry by turning Mountains into stone (though Mountains is a limited resource) or Deep mine for an unlimited amount when set to stone.
Stone can be processed into Cut stone, either through crafting or cheaper by a Stonemason.
Stone is not renewable through Quarry, but is through Gatherers (although slow) and especially Deep mines (reliable: an unlimited amount available if set to stone).