You would expect to find most schoolboys glued to their Xboxes or honing their football skills when not in class.

Not many would have created a growing handmade jewellery business – before they even hit their teens.

Meet Josh Gringras, the 11-year-old creator of Jewellery By Josh, who has channelled his magpie-like fascination with jewellery into a fledgling business.

The pupil of Heathside Preparatory School, in Heath Street, Hampstead, sells his handmade earrings for £6 to £10 per pair at the West Hampstead Sunday market in Iverson Road – but his ambitions do not stop there.

The budding entrepreneur said: “People have said our jewellery is amazing. They are generally very impressed and have even suggested new ideas, such as cufflinks.

“There is a lot of demand at the moment, and we’re looking to expand.”

Josh designs and creates the products but has enlisted his older brother David, 13, to build the website and their friend Joseph Rosenfeld, 13, to help with marketing and sales.

David and Josh, who live in Cricklewood, were born with multiple health problems, including cleft palates.

Fortunately, they were able to have cleft palate surgery before they were six months old. They are both motivated by this to help others who are not able to access this care.

That is why they donate 20 per cent of all sales to charities The Northern Cleft Foundation and Best Beginnings.

David said: “It’s not only about the earrings, its about the difference it makes – we were so lucky in our positions and because we have the chance to raise money for people like this, we do.”

The Northern Cleft Foundation, a charity for children in India with cleft palates, is particularly close to David’s heart.

“If we had been born in India (where the charity operates) we would not have had our operations, would have been outcasts in society and we wouldn’t have been able to breathe or speak properly and there’s so many other problems,” he said.

As an aspiring doctor, David has saved up his Bar Mitzvah money to go to India with the charity and assist in caring for the children, as well as having the rare opportunity to watch surgical procedures take place.

They also support the Best Beginnings charity founded by their mother, Alison Baum, which aims to reduce inequalities in UK child healthcare.

The remainder of the money generated from selling their earrings is re-invested in extra beads and other equipment Josh uses to make his very colourful creations.