Turning glass to gold

Firozabad is India's glass capital, most famous for producing traditional glass bangles. But the city is the source of another treasure – one that's hidden and extremely hard-won.

"He burned the sari and from it, handed us a thin slice of pure silver," said my mother, describing a moment that had taken place 30 years ago at her home in the city of Firozabad. The man in her story was no magician, but an extractor. Like many similar artisans in my mother's hometown, he'd go door to door collecting old saris to mine them for their precious metals.

Until the 1990s, saris were often threaded with pure silver and gold, and I remember digging into my mother's wardrobe, searching for her glittery outfits like treasure. But as she told me, the extractors were looking for something even more valuable than clothing – they were looking for trash, and a kind of trash specific to this city.

For some industrious artisans, the city was nothing less than a gold mine – a place where the precious metal once trickled through the sewers.

Founded in 1354 CE by the sultan of Delhi, Firoz Shah Tughlaq, Firozabad was built as a palace city that, according to court historian Shams-i-Siraj's writings, was twice the size of the walled city of Shahjahanbad (today's Old Delhi, devised by the same ruler who built the Taj Mahal). According to Rana Safvi, historian and author of The Forgotten Cities of Delhi, it was "used as a prototype for later Mughal-era fortresses, as this was the first time the concept of a Diwan-e-Aam [audience hall] for the public and a Diwan-e-Khas [private audience hall] for the nobles was introduced."

Which is why it was so surprising to me that after several trips to the city and discussions with locals and residents involved with the glass industry, I learned that Firozabad creates another precious commodity, one that only emerges after the bangles are made: gold.

Traditionally, glass bangles produced in the city were decorated with pure gold polish. This meant that many other items used during the process came into contact with the precious metal: the bottles and containers filled with polish, the fabric scraps used for buffing, the baskets that held the refined bangles, and even bits of broken bracelets themselves. This gold-coated waste from bangle factories and workshops, and from the homes of the craftsmen, was often disposed of in the city's sewage pipelines, essentially creating a secret stream of potential wealth. Once collected and cleaned, this waste was mined to extract the metal.

"For those oblivious, these materials are nothing more than trash," said Mohammad Sultan, who owns a jewellery store in Firozabad. "But those familiar with the metal know the true value of this 'trash'."

Sultan himself has worked as a gold extractor for more than 25 years, and explained that the technique of wresting the metal from these discards is presently known by only a handful of artists – and that it varies depending on the item.

"The disposed bottles of gold are left in a bucket of thinner or turpentine for a few hours to remove the gold residues," Sultan explained. "The residue sets on the surface of the thinner and is then wiped off with a piece of fabric, which is allowed to dry and is finally burned to ashes. After this, the ashes, with the addition of a few chemicals, are set on a thick layer of sand on a stove or heater, which is allowed to heat until the ashes turn into liquid. Once the liquid cools down, it transforms to the glass leaving behind the gold residues which now rests below the sand."

BBC