Ahmedabad: Eighty-year-old Ganga Gohel painstakingly sweeps the narrow streets of Sheth Ni Pol in the Ratan Pol area in the walled city of Ahmedabad, well before the municipal corporation workers turn up. To all intents and purposes, she looks like an old lady eking out a living by keeping the 25m-long street clean.

The truth is that she pays Rs6,000 for the privilege. For that money, Gohel gets to sweep three streets for gold twice a day. Her monthly takings after that fee—Rs15,000.

Gohel is a dhul-dhoya, literally dust-washer in Gujarati. She is one of around 200 people who comb Manek Chowk and Ratan Pol, which has more than 5,000 jewellery manufacturing units, shops and bullion trading houses.

“I collect and sieve dust from the garbage and sell it to a bigger dhul-dhoya (a wholesale buyer)," Gohel says. “They refine the dust and turn it into gold and sell it to the jewellers."

Gohel has been doing this job for over four decades and the income has helped her raise two daughters after her husband died some 30 years ago.

According to Shree Choksi Mahajan, Manek Chowk, an association of bullion traders and jewellers in Ahmedabad’s walled city area, the total daily turnover of the Manek Chowk and Ratan Pol bullion and jewellery industry is about Rs25 crore per day.

“As a manufacturing house, when we make jewellery or refine gold, some portion of the precious metal is lost as it turns into fine dust, flies out in air and gets mixed with dust in the street," says Bababhai Soni, owner of Ambica Touch, a bullion-testing lab in Ratan Pol. “We cannot get this lost portion back as we don’t have people and time to sweep streets."

Soni has also been operating gold refining and jewellery manufacturing facilities in the same area for the last three decades.

Gold rush: Ganga Gohel, who has been sweeping the streets of Sheth Ni Pol for the past four decades, makes Rs15,000 a month. Mint

The wholesale buyers pay Rs800-1,000 per 500g of washed dust depending on the potential of gold recovery from it.

“After the sweepers sell the dust to us, we wash it and mix it with mercury, which helps us to separate metals from the dust," says a 30-year-old wholesale buyer, who did not want to be named. “This metal dust is further washed with nitric acid, which melts other metals, but keeps gold and silver intact."

The fine gold dust that they get after the nitric acid wash is melted in a furnace for around 10 hours until the temperature reaches 1,000 degrees Celsius. The molten metal is cooled and turned into a plate of raw gold.

“First we get the raw gold tested in the lab. The grade is digitally measured. Once we get a certificate (of caratage), we sell it to the jewellers at the prevailing gold prices," says another wholesale buyer of dust based in Ratan Pol, where the old Ahmedabad Stock Exchange building is located.

On an average, wholesale buyers have to refine as much as 2-3kg of dust to get 10-15g of gold.

“Some jewellers collect dust from their shops for years and then sell it directly to wholesale buyers for lakhs of rupees," says Hiren Soni, who owns a jewellery shop in Sheth Ni Pol. “Wholesale buyers of dust also buy old cushions, doormats and carpets from us and pay us a lump sum, which runs into thousands of rupees."

Not only do they pay for such items, from which they hope to extract gold dust, they also replace them with new ones.

While Bababhai Soni contends that the dhul-dhoya tradition benefits all participants in the system equitably, his son Nitesh says that occasionally the dust-gatherers can get lucky.

“Though rarely, we do lose small nuggets of gold or smaller loose parts of jewellery in the basin at times while washing it with chemicals," says the younger Soni. “These sweepers who clean the drainage often find these lost nuggets. It’s like a jackpot for them."

But, like much else, the advancing tide of technology could spell the end of the dhul-dhoyas.

The new methods minimize metal loss during the manufacturing process, says Harshwardhan Choksi, president of of Shree Choksi Mahajan, Manek Chowk. That will make it more difficult to find gold in the dust of Ahmedabad’s streets.