Mask of Vaikuntha Vishnu, late 5th century. Learn more about 5th century masks
A technology for drilling developed during the Mature Phase (c. 2600–1900 BCE) of the Indus Valley Civilisation. It was made from stones such as chert and jasper. Two types of drills have been excavated from the Indus Valley sites, namely, tapered cylindrical drill and constricted cylindrical drill.