Wootz’s Steel
Wootz steel originated in South India, in Tamilakam present day Tamil Nadu and Kerala, and ancient Sri Lanka (Tamraparni). [6][7] The Chinese and locals in Sri Lanka adopted the production methods of creating wootz steel from the Chera Tamils by the 5th century BC. J.D Verhoeven and Alfred Pendray reconstructed methods of production, proved the role of impurities of ore in the pattern creation, and reproduced Wootz steel with patterns microscopically and visually identical to one of the ancient blade patterns.
Source: en.wikipedia.org