By Bappa Majumdar

KOLKATA, India, Nov 9 (Reuters) - As 70-year-old Mohammed Omar sifts through grime in the back lanes housing Kolkata's ornament makers to pick out gold dust, his deeply lined face furrows with worry as again he finds nothing.

For centuries, the city's band of more than 200 gold scavengers, have eked out a living by panning out gold dust. But demand for jewellery has fallen alongside bullion's climb to a near three-decade high.

World gold prices <XAU=>, at above $830 an ounce, have risen 12 percent in the past month alone and are up more than 30 percent this year.

"Business is at its worst. People like us are on our way out as silver and pearl jewellery are now more in demand," said Omar, his voice choked with emotion.

"There is less work at factories and less gold dust available."

Even as Indian customers thronged jewellery shops during the festive Diwali season undaunted by the sky-high prices, many also walked away empty-handed, promising to return when prices eased.

Indians consider it auspicious to buy gold during Diwali, the Hindu festival of lights, when the goddess of wealth, Lakshmi, is worshipped. The period from October to February also coincides with the marriage season, when parents give their daughters gold jewellery as a dowry.

For Omar, his plight couldn't be worse during this time of plenty. With his daily earnings dwindling to just a dollar from five previously, he struggles to feed his nine-member family.

"Earlier, we never used to go to bed hungry," Omar said. "Now, we are lucky to get a full chapati during our meals," he said referring to a type of Indian bread.

Each day, Omar and his band of "Kadaiwallahs" -- men who wield large pans -- rise at the crack of dawn to catch goldsmiths sweeping their shopfloors and set about scouring the debris for gold speckles.

They separate gold by burning out the impurities with acid and bringing them together with mercury drops in vessels, a traditional brand of alchemy that dates back to the rule of the Mughal kings in the 16th century.

But their world is falling apart, thanks to shifting gold market dynamics.

MEASLY MORSELS "All that does not glitter can be gold," said 35-year-old Mohammed Aqeel, his gold tooth catching a gleam from the early morning sunshine.

"I remember selling gold worth 5,000 rupees an ounce, but those are rare moments now. Perhaps they will never return again," he added, wistfully.

In fact, business was so good seven years ago he could replace a broken tooth with a gold one easily, he said.

This week, he had only a 700 milligram gold piece to show for three days of back-breaking work.

By contrast, "Kadaiwallahs" used to be able to accumulate about one gram of gold after a few hours of work, earning up to 6,000 Indian rupees, or $153, a month.

"Business is not so good and we have to work for hours to ensure that not even a speck of gold is lost," said J.V. Soni, a goldsmith worker in Manekchowkl gold market, in the western Indian city of Ahmedabad.

Gold dealers said sales were sluggish during the festival season and at best were likely to be on par with last year, but demand in eastern and southern India have been especially hard hit.

And the situation is likely to worsen, with gold prices expected to touch $900 an ounce by March next year on a slumping dollar, soaring crude oil prices and signs of more interest rate cuts in the offing by the U.S Federal Reserve.

The gold scavengers don't need price charts to know the writing is on the wall.

"I have never been to school, but I think my younger brothers must study or they are doomed," said 17-year-old Mohammed Bilal. "People tell me that the prices are unlikely to come down any time soon," he said. "Our pickings are becoming smaller by the day.

"Shops and gold processors have started to shut down. We will have nowhere to go at this rate," said Mohammed Bashir, a 45-year-old gold scavenger. ($1=39.32 rupees) (Additional reporting by Rupam Jain Nair in Ahmedabad) (Writing by Biman Mukherji; Editing by Ben Tan) (([email protected]; Reuters Messaging:[email protected]; +91-9831608877)) Keywords: INDIA GOLD DUST/