Assembled during the tenure of Chandragupta II, this Quwwat ul Islam Mosque situated in Delhi is another marvelous sensation of incredible metallic work. The Iron Pillar of Qutub Minar, which was constructed about 1600 years ago, has not experienced a single layer of iron rust to date. The unusual wonder has a height of about 7.21 meters, weighs around 6 tons, and has a diameter of about 41 centimeters. It has been exposed to every type of weather condition, but still, it didn’t even get a single coat of rust. Considering this unusual phenomenon, scientists and metal workers across the world remained curious about its magnificent properties for decades until, in 2003, they got their answers.
The metallurgist at Kanpur IIT has finally published his findings in a published research paper stating that the pillar was built using a “futuristic technique” and, due to these aspects, it has become rust-resistant. Moreover, the co-author of the study, R. Balasubramanian, regarded this pillar as “a living testimony to the skill of metallurgists of ancient India.” He wrote that a protective layer known as “misawite” had been engrossed in the erected structure at the time of its formation. Due to its presence, the pillar becomes rust-resistant.
It works by forming an amorphous iron oxyhydroxide layer in between the metal and rust and contains a high concentration of iron. Owing to this, the pillars resist iron rust. Furthermore, it has been stated that the iron that is available today has a phosphorous content of up to 0.05%, while the iron that was being used in the construction of Qutub Minar contains a phosphorous content of up to 1%. However, today, workers and engineers eliminate the concentration of phosphorous from iron in order to prevent it from tearing apart. But the architects of that time preferred to keep phosphorous in it and further strengthened it through the use of hammers.
In this way, the phosphorous became further engrossed in the pillar, thus making it even stronger. As we know that people start to associate their beliefs with ancient marvels, and this happened with this old iron pillar as well. As more and more people linked their good luck to the pillar with the condition of “wrapping their arms around the metal structure and touching the tips of their fingers”, the color of the pillar’s base started fading, which was also helpful in preventing it from rusting. Seeing this, the authorities wrapped a protective fence around it to counter further damage, and hence, this magnificent pillar has stood to date without any layer of rust or an issue of discoloration.