They sell anything that they can. The rocks go through crushers and then the belts run them up to the shakers that usually have 3 screens with different sizes ranging from 10 inch down to 3 inch or what ever size they can sell, and then into the bottom to bins.
Often times they will separate them through more shakers for different sizes all the way to sand, or gravel. Most rocks and gravel will drop through the shoots into huge bins for the trucks to roll under like they do with grain towers.
Usually the sand and finest gravel will end up on belts that then drop them in piles to be loaded by loaders into trucks to be delivered to landscape companies or for larger bulk orders used for roads and such.
Interestingly, most roads in the Deep south are blacktop because of the type of rock, where as most the roads up North are cement due to the different type of rock and sand they get from Quarrys up North.
It’s like most houses in the deep South are brick, due to the clay in the ground.
“It’s like most houses in the deep South are brick, due to the clay in the ground.”
No point in shipping building materials any farther than you have to. If you hit a lumber store on the west coast you can find redwood but rarely cedar.