The Delhi Iron Pillar has stood rust-free for over 1,600 years — and new scientific investigation suggests it may also contain gold, and that its makers learned their structural logic from natural rock formations.
Prof. T. Jayakumar presents cutting-edge metallurgical research on two ancient Indian iron pillars — the iconic Qutub complex pillar in Delhi and the lesser-known Kodachadri pillar in Karnataka — using gamma radiography, ultrasonic testing, in-situ metallography, and X-ray fluorescence. His findings challenge prevailing theories: the corrosion resistance is likely due to uniformly distributed phosphorus in the iron matrix rather than microstructural features, and the needle-like structures seen in earlier analyses are almost certainly cementite, not phosphorus compounds as previously assumed.
The radiography reveals a dense anomaly in one region of the Delhi pillar consistent with gold or bronze — suggesting the pillar was a devotional object as much as an engineering marvel. The Kodachadri pillar shows dramatically asymmetric corrosion: the western face exposed to Arabian Sea breeze is heavily degraded while the eastern face is nearly pristine — a 1,500-year controlled experiment in material science that modern metallurgists are only now fully reading.

About the Speaker:
Prof. T Jayakumar was associated with the Indira Gandhi Centre for Atomic Research (IGCAR) from 1978 to 2015. Then he taught at the National Institute of Technology (NIT), Warangal from 2015 to 2017. He was also associated with Defence Metallurgical Research Lab (DMRL) from 2018 to 2022.