Basalt pebbles are small, rounded, and naturally tumbled stones formed from the rapid cooling of basaltic lava exposed at or near the surface of the Earth. They are typically dark gray or black in color, due to the rich iron and magnesium content of basalt. Their smooth and polished appearance is a result of the natural erosion process, usually caused by water action over a long period. These pebbles are often used in landscaping, construction, and decorative purposes because of their durability and attractive appearance. Additionally, they can also be found on beaches and riverbeds where they have been smoothed over time by the movement of water.
 
GRANULE SIZE (MM)

8/15
15/30
30/60
60/120
120/200
150/300
+ 300