This natural sharpening stone - when rubbed with a bout and some water - produces a slurry full of microscopic grains: the garnets. This forms a very fine abrasive paste allowing you to polish the edge of any metal blade.
Creating a complete bevel on this stone is possible but will take you some time. Straight razors owner rarely need to recreate a complete bevel.
What they mainly need is a coarser abrasive to revive their edge and that's were the coticule stone comes at hand.
Colticile stones will help you keep your bevels sharp and smooth, this is the reasons why these stones are so requested. It's also one of the rare natural stone able to sharpen all type of steels, even stainless.