Wootz steel is a crucible steel produced by smelting iron with carbonaceous organic matter (leaves, wood) in a sealed crucible at approximately 1,400°C, producing a high-carbon steel (1.5-2%) with a characteristic dendritic microstructure visible as a wavy pattern on the surface. This process, developed by anonymous metallurgists in South India (the Tamil Nadu and Karnataka region) and Sri Lanka between the 4th and 3rd centuries BC, produced steel of extraordinary simultaneous hardness and toughness — normally mutually exclusive qualities — thanks to the heterogeneous distribution of carbon. In 2006, researchers at TU Dresden (Reibold et al., Nature) confirmed via electron microscopy the presence of carbon nanotubes in a 17th-century wootz saber blade, which partly explains its exceptional properties. Exported to Persia under the name fūlād hindī and from there to the Islamic world, it reached Europe as 'Damascus steel', a name that mistakenly identified the distribution market with the place of production. The exact manufacturing process was lost around 1750 and has not been fully reproduced.