Photoluminescent Tumbled Gravel Commonly used gravel and pebbles two kinds.

In concrete construction, aggregate particle size greater than 4.75mm become coarse aggregate, commonly known as stone.
Photoluminescent Tumbled Gravel refers weathered rock formed by the flow of long-term particle transport is no natural corners of pellets 2 ~ 60mm. Sediment classification in one name. The average particle size greater than 1 mm rock or mineral fragments thereof.
Natural rock or phosphorescent sand rocks mechanically crushing, screening made of rock particles larger than 4.75mm in diameter.
glow in the dark pebbles is a natural weathering, water handling and sorting, piled, rock particles larger than 4.75mm in diameter.
C25 strength concrete gravel generally used below.
Overall, the different size ranges pebbles and gravel.