♦Livre♦

A Brief History of Drills and Drilling
8. More recently, we have uncovered preliminary evidence for the use of a drill utilizing diamond splinters as cutting points (Gwinnett and Gorelick 1986). These were used in ancient South Arabia, Iran, and Sri Lanka. It is known that diamonds were abundant in ancient India and that craftsmen learned to haft and use them for drilling. Indeed, the practice is still carried on in Cambay, India. The regular, concentrically grooved sidewall pattern of the parallel-sided perforation (Fig. 12) and a small, central conchoidalfracture pattern at the leading edge of drilling (Fig. 13) are characteristic of this type of drill.