| Abstract: |
A small, amorphous rock crystal artifact from Arikamedu, India, has nine drill holes, all varying in depth
seven of them are incomplete. The diameter of a given hole is consistent throughout, so that the side walls are regular and parallel. The shape of the hole, in addition to the pattern of the grooves on the side walls and a central, conchoidal fracture at the leading edge of the hole, is clear evidence for the use of a twin diamond drill. The use of such drills has been documented at modern Cambay, India, and at Mantai, Sri Lanka (ca. A. D. 700-1000). Arikamedu, which is located in southeastern India, was occupied between 250 B.C. and A.D. 300, thus making the rock crystal artifact the oldest known example of diamond drilling technology.
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