To learn how to craft stone, a carpenter must read the book "Making Valuables with Stonecrafting", which can be purchased from the Gargoyle Stone Crafter NPC located in the carpenter shop in the Royal City in Ter Mur. The book costs 10,625 gold and is consumed once read.
To create stone items, the resource High Quality Granite and a Mallet and Chisel is needed. The tools can be purchased from the same NPC in the Royal City. Costing only a few gold pieces each, they wear out, just like Pickaxes and Shovels. Granite is obtained by Mining.