Green entrepreneur and disruptor Dale Vince has entered a new skirmish over claims made via social media that his Stroud-based business, the Sky Mining Company, fashions diamonds out of thin air.

Wary of the firm's environmental USP whereby "skydiamonds" are created through a patent-pending process to create a unique, carbon-positive product, the Natural Diamond Council (the trade body for the controversial gem mining industry), took a case against selected promotional material to the Advertising Standards Authority.

And the ASA has now backed the Council's complaint and ruled that the firm "cannot use such terminology as '"Diamonds", "diamonds made entirely from the sky" and "Skydiamond" to describe their laboratory-created diamonds in isolation without a clear and prominent qualifier".

Skydiamond has had an excellent press since the company launched in 2021 and has rattled the tiara of an industry which appears to be increasingly out of step with the luxury goods market's quest for ethical products.

Vogue magazine reported: "Skydiamond isn't simply aiming to be carbon neutral, but climate positive - removing more greenhouse gases from the atmosphere than you are producing - and dazzlingly so."

Visitors to the Skydiamond website are told: "While natural diamonds are cherished for their beauty, the mining process can carry significant environmental and social impact, with often hard-to-monitor working conditions, leading to loss of habitat for wildlife, deforestation, soil erosion, and water pollution."

And while synthetic diamonds can also necessitate large amounts of coal or gas to produce, the Skydiamond-made product, created in Stroud, uses only CO2, wind, sun and rain, with all renewable energy coming from sister-company Ecotricity. This makes the resulting diamond, the company said, the only carbon positive example in the world.

In reaction to today's ruling, Mr Vince took to X, formerly Twitter, to vow to lodge an appeal against the ASA's decision. 

He said: "The ASA has made a mistake and we are appealing this ruling. Our website and all of our marketing for @skyminediamond, indeed our very name, makes clear that our diamonds come from the sky, we make them or mine them from the sky... Nobody could possibly think that they are conventional stones ripped from the bowels of the earth at enormous environmental cost – and nobody actually has."

He added that the trade body's complaint stems from diamond mining companies "like De Beers - it is an attempt to use the ASA for anti-competitive purposes and it's utterly baseless."