Digging (in dirt patches) is a method used to obtain several important resources, including cut stones, gypsum and bauxite, and red sand. The process is extremely labor-intensive and requires a group of people with shovels working together.
Shovels are created at a Carpentry Bench using 1 board and 1 shovel blade. Those who have passed 2 or more Architecture tests can create one Fine Steel Shovel per month using 1 board, 1 shovel blade, and 1 steel blade. Those who have fitted an Octec statue with a double set of Octec Crystals may produce one Diamond Tipped Shovel per month using 1 Fine Steel Shovel and 80 small diamonds.
Holes can only be dug on patches of dirt. Dirt patches are actually rather uncommon in Egypt -- grass, sand, and rock are far more common terrain types. Dirt is colored similarly to clay (but lacks the cracked appearance of clay) and, like clay, tends to be found near water.
To create a hole, you must be standing on dirt and be carrying a shovel. (No special skills are required.) Then, from your "Projects" submenu, choose Stonework, followed by Dig a Hole. A modest-sized hole will appear at your feet.
Left to itself, a hole will gradually shrink, close up, and ultimately disappear. To keep it open (and make it larger), you must continue to dig the hole. Anybody carrying a shovel may keep digging by simply clicking on the hole. Digging is a tiring activity; thus you must rest before you can dig the hole again, the rest time depending upon your Endurance. A productive dig requires multiple diggers as well as a good supply of Endurance food.
The more a hole is dug, the larger it can grow. Larger holes yield more of whatever resource is produced there. A Fine Steel Shovel provides 1 1/2 times as much "digging power" as a regular shovel; a Diamond-Tipped Shovel provides 2 times as much digging power.
As a dig progresses, the resources being dug up will appear on the ground around the hole, free for anyone to pick up. A common strategy for digs is for one or more trustworthy participants to act as "pickers", collecting the resources as they appear and stashing them in a nearby chest, to be distributed among all the participants when the dig concludes.