Weathering first
Freeze-thaw prises rock apart, plant roots widen cracks and rainwater slowly dissolves minerals. Nothing has moved yet — this is breakdown in place.
Then transport
Gravity, rivers, ice and wind carry the fragments. Along the way, pieces knock together and round off, getting smaller with every kilometre.
Arrival at the coast
Quartz survives longest, which is why most beaches are pale and quartz-rich. The whole journey takes tens of thousands to millions of years.