Today’s image shows beach ripples at Vlieland’s North Sea beach. When a coastal tide rolls out, it can reveal beautiful ripples in the temporarily exposed sand. The spacing between ripples is proportional to the depth of the water and the size of the waves that molded them.
Sand is a size-term – any type of rock or mineral material that is 0.06 mm to 2.00 mm in diameter. Tan-colored beach sand is primarily made of quartz grains. Quartz is hard and often remains after rocks erode.