1 ¼” Minus (With Fines) Posted on September 3, 2013 by Michelle Andreas in earth products, gravel, products Description Crushed rock with a particle size of 1 ¼” minus with fines. (Color: blue grey or dark grey) Also referred to as C.S.B.C. = Crushed Surface Base Course Application Typically used as a base rock but can also be used as a top course.