(IDEX Online) - Diamond buyers are prepared to pay an extra 20 per cent for the peace of mind that their purchase has a guarantee of sustainability.That's among the key findings of De Beers' eighth annual Diamond Insight Report, published today and titled Sustainability: shaping the future of the diamond sector.It found that over half (56 per cent) of consumers would pay a premium of 10 to 20 per cent for natural diamond brands that "could demonstrate they operate in an environmentally and socially responsible way."It also said: "Nearly 17 per cent of these consumers were open to paying 25 per cent or more for a sustainable natural diamond."Researchers quizzed over 8,400 people globally across seven key consumer markets for diamonds for the report.Six out of 10 said they'd deliberately bought a product (not necessarily jewelry) made in a more environmentally or socially responsible way.Bruce Cleaver, CEO of De Beers Group, said in a foreword to the report: "These findings highlight that sustainability is more than the right thing to do; it is critical to maintaining consumer desire, trust and loyalty. "The diamond industry has a significant opportunity to demonstrate its sustainability credentials to a new generation of consumers who value actions and evidence over rhetoric."