Which Grade of Limestone Is Right for Your Needs? | Port ...
Mar 19, 2018· Grade #610S tan Calica stone and grey limestone (¾ of an inch) can serve independently as the top layer. A finer grade of onehalf inch, Calica stone and grey limestone #57G or, even finer at 1/4 inch, limestone #8G are also options for loosetop driveways. Both are attractive, decorative and functional.