Marion Cotillard has teamed up with Chopard to create ethically sourced jewellery.

The 'The Dark Knight Rises' star - who recently joined the Swiss brand's co-president Caroline Scheufele and producer Livia Firth in promoting the importance of ethical labels - has designed a necklace and bracelet, which features opal stones mined from a family-owned business in Australia.

She said: ''You design while thinking of the people who work on extracting the stones, so it's a totally different energy.

''Why should the creation of dreams and luxury turn into a nightmare for the people who are providing the raw material?''

The 39-year-old actress - who also sported Chopard's Green Carpet Collection at the Cannes Film Festival in 2013 - will unveil her designs in May when the festival kicks off once again.

Livia - who is the wife of British actor Colin Firth - is thrilled with the team up and described the process of using ethically obtained stones as a ''new direction'' for jewellery making.

The star has also produced a film entitled 'The True Cost' which explores the immoral side of the high street fashion industry which will debut at Cannes.

She explained to WWD: ''It's really a journey into fast fashion and, I'm not sure how to say it politely, but basically how f**ked up this whole thing is.

''Things are complicated and murky and totally unjust and wrong, so it's a big call to reform, a big call to consumers to try to take a step back and start consuming maybe a bit more consciously.''