By Tom Heap
BBC News, Bangalore
The global building boom and the fashion for smart interiors has created huge demand for natural stone.
Many quarry workers are children
In the past few years this has been fed by a booming export trade from countries where rock is plentiful and labour is cheap.
India is among the most rapidly growing sources of granite, slate and sandstone.
But now questions are being asked about the cost to the environment and the human toll for workers.
Highly-polished kitchen worktops and gleaming stone cladding in the washroom were once the preserve of the very rich, but now, thanks to the exploitation of new sources, the price is plummeting.
In the UK, natural stone has been vigorously endorsed on gardening and interior design television programmes, the resulting appetite increasing granite imports from India to Britain eight-fold in the past five years.
Our investigations into how the stone was being produced focused on Bangalore in the southern Indian state of Karnataka.
People have found it easy to just walk into the forest and start mining
Environment Support Group
The first quarry we visited was north of the city near Mount Shivaganga.
The workers there were completely without protection for their hands, feet or eyes, and spent their days splitting blocks with hammer and chisel.
Their pay is around £1.50 ($3) a day.
Twelve migrant workers slept in one room. Most were once farmers who had been driven from their land by drought.
Despite the tough work, low pay and health and safety standards illegal in the West, there was little sense of misery or desperation.
The next stop had blocks of stone about the size of a camper van piled up ready for export.
Chipping away at them was a man with one leg. He had lost the other in a quarry blasting accident.
He still worked knocking off the rough edges.
There was more evidence of management here and our inquiries about pay and conditions resulted in few answers and being escorted off the premises.
Indian quarry workers have little safety equipment
The following day we travelled south of Bangalore and walked into a granite quarry where old women and children were breaking rocks.
We spoke to one family, all nestled under a windbreak in a dusty bowl.
It emerged that the father had taken a loan at the beginning of the year from the quarry's owners and had to work until it was paid off.
This is what is known as bonded labour and leaves the family tied to the job.
The father told me he would be returned by force if he tried to quit.
Once again, despite the harsh conditions, the family showed great dignity and resilience.
They do not like living in a quarry but they have to eat.
Leo Saldhana of the local Environment Support Group said quarry owners were taking advantage of people's desperation by employing children and paying low wages.
India exports around 14,000 tonnes of granite a year
He also warned that many new holes were being illegally dug in forest parks.
We saw one mine amid the jungle where giant blocks marked for export were waiting to leave.
"People have found it easy to just walk into the forest and start mining," Mr Saldhana said.
"Obviously it means the government has failed in regulating... and senior bureaucrats have colluded to just look the other way when this has been happening for the last five or six years."
We tried to get a response to those accusations of corruption from the government in Bangalore but a mixture of refusal and confusion thwarted our plans.
So what should the concerned stone buyer do?
Neither the workers or the welfare groups want shoppers to abandon Indian stone, but they want us to ask the right questions, seeking guarantees that it was quarried without child labour and environmental destruction.
But clear answers will be scarce - little stone is bought straight from the ground but more often through dealers who source from across the country.
So consumer pressure will not eliminate the abuses, but greater awareness encourages the business to clean up its act.