History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c13.s4.2

v1.c13.s4.2

The other possibility is that the initial metallic nuggets might have been brittle due to the presence of oxide and sulphide inclusions or separation of some other phase on cleavage planes such as separation of Ni on Widmannstat planes in meteoric iron. Such nuggets will break into pieces having sharp edges. In such a case the concept of cold working metals may be associated with the casting technology because, according to Tylecote some of the early copper objects (3000 B.C.) have been found to show the structure of annealed and recrystalised metal.