Jul 27, 2020· Specialty Crushed Stone 57 This category refers to a stone that is about 3/4 inch long. Most typically use it for concrete mix, landscaping, and drainage. 67 Crushed stone 67 includes stone that is 3/4 inch or smaller in size. 67 is a great material for road and slab base as well as fill. Estimated Reading Time: 2 mins Live Chat