Like all Power Cells the Stone Mining Cell is also an all-purpose-tool for pulling blocks, except for ore. Stone Mining Cells can be found in Obsidian Treasure Chests on the Stalactite layer underground sometimes, or can be crafted in your Crafting Menu (default key "Q") or at Crafting Tables (which still exist in older worlds created before R22 on September 16th 2015). The crafting-recipe needed to craft Stone Mining Cells will be unlocked by receiving a Wood Mining Cell - after crafting it yourself or taking one from a Stone Treasure Chest (or from a friend's chest/bag)