Every year, the world consumes around 50 billion tonnes of sand, gravel and crushed stone. The astonishing scale of this demand is hard to comprehend – 12.5 million Olympic sized swimming pools per year – making it the most-used solid material by humans.
Most of us don’t see the sand and gravel all around us. It’s hidden in concrete footpaths and buildings, the glass in our windows and in the microchips that drive our technology.
