The Iron Pillar of Qutub Minar, the 1,600-Year-Old ancient wonder that refuses to rust

The Quwwat-ul-Islam Mosque complex in New Delhi is home to an ancient wonder of metal work, a 1,600-year-old iron pillar that has continued to capture the imagination of scientists since the early 1900s, owing to its exceptionally resistance to rust.

The often called Iron Pillar of Qutub Minar and dated back to AD 402, measures 7.21-meters-tall, has a diameter of 41 centimeters and weighs about 6 tons. It is thought to have been erected elsewhere, perhaps outside the Udayagiri Caves, and moved to its present location by Anangpal Tomar in 11th century.
Now positioned right in the middle of the courtyard of the Quwwat-ul-Islam Mosque, the pillar is nothing out of the ordinary, as the tapering black column could be just another piece of architecture from ancient India. There is a deep socket on the decorative top of the pillar, where a statue of Lord Garuda, or the ‘Sun Bird’, might have been embedded, a feature common to many such pillars of the time. However, when you look close, you can perhaps see it for the miracle it is, and not just in its fabled wish-granting capabilities but its extraordinary feat of resisting corrosion for over 1,600 years in the face of the extreme temperatures and rising pollution in the Indian capital.

It’s more than a millennium and a half old, believed to have been erected during the reign of Chandragupta II, one of the most powerful emperors of the Gupta Empire. And, even though it has spent all that time outdoors, it shows almost no sign of rust damage.
For decades, scientists and metal workers from all over the world speculated about the properties of this unusual marvel, and it wasn’t until 2003 that the mystery was finally cracked.
There was a time when many believed that the rust-resistant pillar was made out of some mysterious, non-earthly metal, while others speculated that whoever made it used a futuristic technique that was lost in the mists of time.
The second option is technically true, as metallurgists at Kanpur IIT.
R Balasubramanian, co-author of the study, called the pillar literally a living testimony to the skill of metallurgists of ancient India, explaining that the wrought iron structure features a protective layer called “misawite”, an amorphous iron oxyhydroxide that forms a barrier by adhering next to the interface between metal and rust. Ita formation is caused by the high phosphorus content in the iron.

If modern iron has a phosphorus content of under 0.05%, the wrought iron that the Pillar of Qutub Minar is made of contains as much as 1 percent phosphorus. According to Dr. Balasubramaniam from the Indian Institute of Technology, instead of removing the phosphorus from the iron as workers do today to prevent the metal from breaking up, they kept it in, and simply pummelled the pillar with hammers to push the phosphorus from the core towards the surface. This kept the iron strong, and also led to the formation of the misawite barrier.

Sadly, as is often the case with these ancient wonders, they are very vulnerable to humans.
Having gained a reputation for bringing good luck to whoever managed to wrap their arms around the metal structure and touch the tip of their fingers, more and more people engaged in the practice over the years, which led to a visible discoloration of the pillar near its base.
Tourist guides in the area will also tell visitors that if they can wrap their arms around the pillar and make their fingers touch, it is also a sign of faithfulness to their lovers.

Either way the pillar has continued to engage the imagination of many as one of the world’s most compelling historical mysteries, not just in its composition but also in its origin. An inscription on the pillar that dates back to the fourth century calls it a “Vishnudhvaja” (a flagstaff of the Indian god Vishnu) that was placed on a hill known as “Vishnupada” to commemorate a king named Chandra.
A translation of the six-line inscription by John Faithful Fleet, an English civil servant who was also a historian, epigraphist and linguist, in 1888 says a powerful monarch by the name of Chandra, who “carried a beauty of countenance like the full moon, having in faith fixed his mind upon Vishnu, this lofty standard of the divine Vishnu set up on the hill Vishnupada”.
However, the identity of King Chandra remains a mystery, although he is generally identified as the Gupta emperor Chandragupta II.
And there is also much confusion around the origins of the pillar itself. According to some, it was built by Chandragupta II, who ruled between 375 BC and 415 BC, established in the front courtyard, facing a Vishnu temple on top of a small hillock called Vishnupada, at Udayagiri in Madhya Pradesh, and was later moved by Sultan Iltutmish in 1233 from its original location to the Qutub complex in South Delhi.
There is also an interesting legend connecting the name ‘Dilli’, local pronunciation of the city, or ‘Delhi’, with a Tomara king and the famous Iron Pillar.
As story goes, the Iron Pillar was designed to be the standard of Vishnu and meant to be implanted into the hood of the celestial serpent on which the earth rests. At the same time, a curse was pronounced on anyone who tampered with it. The Tomara prince, who had the pillar installed in Delhi, wanted to make sure that it had been planted deep enough to enter the hood and had it dug up.
The base was found smeared with the serpent’s blood, the curse took its course, and the Tomara Dynasty declined.
The event was recorded in a verse: “Kelee to dheelee bhaee, Tomara bhava mat heen” or “the pillar was loosened, and the Tomar lost his head.”
Thus some people argue that “Dilli” is a pun on the word “dheele”, meaning “loose”.

Surely the Iron Pillar of Delhi is an archaeological marvel, but also a melting point of the past and the present, history and science, and imagination and legends.