One million children aged between five and 17 are engaged in small-scale mining and quarrying worldwide, according to the UN International Labour Organisation (ILO).
In Africa, the ILO estimates that children under the age of 18 constitute 30-50% of the total workforce in small-scale gold mines.
A boom in Burkina Faso's gold mining sector over the past three years has made the country the fourth leading producer on the continent, but it is also luring children out of school.
In 2003 the government revised its mining laws to encourage investors, and between 2007 and 2011 several industrial mining sites opened in the West African country.
"The exact number of children abandoning schools for the mines in is still unclear," says Moussa Ouedraogo at the Ministry for National Education and Literacy.
"Many schoolchildren are known to work in mines full-time, where they crush stones, sieve dust, transport water and cook," he says, "while others go to the mines during school off-days and school holidays."
It is a familiar story across the continent. An estimated 15,000 children are working in gold mines in western Kenya's Nyanza province.
"When you look at the levels of school drop-outs, the closer a school is to a gold mine, the lower the school attendance," says the regional education director, Geoffrey Cherongis.
Emily Waga, a children's officer in Migori, notes the dangers of involving children in gold mining, both in terms of losing school days and damaging their health,
"We rely on the goodwill of people to report cases, but this doesn't happen often because parents encourage their children to seek employment at the mines," she says.
"When people are poor, nothing that brings in income is dangerous," she adds.
Although West African gold is not as high-grade as gold from South Africa, 1g (0.03oz) can still sell for about $36 (£22) on the world market.
However, a child working at a mine will be lucky to receive $1.20 for a day spent searching in a stream for glistering flakes.
One child says it beats going to school on an empty stomach.
"I would rather work here at the mine and at the end of the day they will give me money to spend," he says.
"We are told those who have employed us are rich, but me, I just want a little money to buy good clothes and food for my mother.
"Even my parents say what I am doing is right. I can buy my own clothes," he adds. "What is the point of being in school?"
Another teenager says: "You need to work hard and wait for your luck. I can't go back home until I get something, because people will laugh at me."
"A parent will find it hard to send a boy to school when he can bring back income that very evening when employed at the mine," says Jack Omora, a government official in one of Kenya's mining areas.
He says his efforts to persuade parents to keep their children in school have been in vain.
"One thing that has held us back is that while we promote education, there is little to end the cycle of poverty that creates this problem in the first place," he says.
"The mining impact goes beyond the education sector," says the Burkina Faso Education Minister Koumba Boly.
He is worried that the country's overall development could be undermined if education is badly affected and notes that a decree was issued when schools re-opened in September, banning all children from mining sites
Rural poverty coupled with record world gold prices is proving an irresistible pull in the Madagascan town of Ankavandra, where it is predominantly girls who are dropping out of school.
"Girls do this because the boys usually have to look after the zebu," says one 12-year-old, referring to the distinctive hump-backed cattle.
The work is physically demanding. The sides of the river bank are hacked out and the soil and rocks piled onto wooden bowls, which are then taken to the nearby stream to be panned.
There are about 150,000 gold panners in the country, producing 3-4 tonnes of gold annually.
The UN's Human Development Index - which ranks Madagascar at 135 out of 169 countries, based on the average life expectancy, education, and income - estimates nearly 70% of the island's 20 million people live on $1.25 a day or less.
Children can earn $14 for working a six-day week looking for gold, which is more than double what they could earn doing other menial tasks such as washing clothes.
The girls say they do the work with their parents' blessing and the proceeds are used to buy clothes and food.
There is little chance of any change in the situation until governments in the gold-mining countries back their own legislation to prevent children working in mines.
However, as the mining sector has the means and influence to protect its own interests, that it unlikely to happen any time soon.