Minerals and Metals in Ancient India v1.c20.s3.t8.4

v1.c20.s3.t8.4

The presence of well-processed and extremely hard wooden sleepers or beams and columnal dressed stones in a 500 BC apsidal structure also indicate early use of iron equipments at Ujjain. Two centuries later (273-236 BC), the Aśokan craftsmen must have used hard steel or carburised iron chisels to excavate quartzose gneiss of the Barabar hills of Bihar and to finish the shafts and pillars of Chunar sandstone.