VISITORS to the Egyptian Galleries at the British Museum are often impressed by the crisp lines and clarity of hieroglyphic inscriptions up to 5,000 years old, and the delicate detail on images of Pharaohs and their exotic deities.

The crispness is due to the hardness of much of the stone used in Ancient Egypt, including red granite from Aswan, purple porphyry, quartzite and various marbles. Some types were so prized that the Roman Emperors had them shipped to adorn their capital, as with the giant columns of the Pantheon, from a source between the Nile and the Red Sea.

There have been numerous speculations about how the Egyptians worked these hard stones; now Denys Stocks, a specialist in ancient technology, has reported on the results of many years’ experiments in making and using tools like those used in Pharaonic times. In a new book, Experiments in Egyptian Archaeology, he notes that flint, one of the earliest material used by mankind, is still one of the best materials for working the hardest stones.

“Flint chisels, punches and scrapers were the only tools capable of cutting and incising hard stone objects, including obelisks and statuary, particularly those of igneous stones such as granite, porphyry, diorite and basalt,” he says. “Craftworkers developed practices that relied on a diverse range of natural materials obtained from the local environment, of which the most important were desert sand, flint nodules, and copper ores.”

The sand was used as an abrasive, with reed or copper tubular drills and copper stone-cutting saws, to work stone vessels, sarcophagi and building stone such as that used for the Pyramids. The waste products included a fine powder mixing sand, stone and copper particles, which seems to have been the raw material used for making the blue-green glazed compound known as faience. This was moulded into all sorts of small objects, notably the human shawabti effigies deposited in tombs to act as servitors in the afterlife.

The origins of copper tools can be found, Stocks suggests, in earlier flint implements such as the endscraper, sickle, and wavy-edged knife. These “were copied in copper to make the chisel, the adze, and the serrated woodcutting saw”, he says.

Stocks made replicas in copper and bronze, and subjected them to hardness tests that showed that even the hardest bronze could effectively cut only soft limestone, gypsum, steatite and red sandstone, together with wood: harder rocks required flint. He also investigated ancient methods of casting copper and bronze into single-use sand moulds and reusable pottery moulds. the resulting tools were then used in cutting and drilling experiments.

The Ancient Egyptians used clusters of furnaces to make large tubular drills and stonecutting saws, Stocks says, and multiple drills to make many beads at once, both early forms of mass production. The multiple drill lowered the price of jewellery manfacture and made such ornaments more widely available to a larger cross-section of Egyptian society, he argues.

Experiments in Egyptian Archaeology: Stoneworking technology in Ancient Egypt. Routledge, £75.