Weight: Approx. 2800 lbs. per cubic yard Base Stone (2a Modified) /yd. 311 Uses: Base under patios and walls Source: County Line Quarry crushed gravel Weight: Approx. 3000 lbs. per cubic yard Stone Dust /yd. 310 Uses: Thin layer under patio stones Source: County Line Quarry crushed gravel Weight: Approx. 3000 lbs. per cubic yard Concrete Sand /yd.