I regularly get asked about stone hatch patterns - where to find them and what to do with them once you do find one that suits.
I was working on a job recently and needed some different type stone hatch patterns. A Google search should give you plenty of options - I found some useful ones here - http://www.eldoradostone.com/trade-community/specification-library/hatch-patterns/
Once you have downloaded the files (they will be in .pat format) what do you do with them? The best solution is to copy all of your custom hatch patterns to a folder (C drive or network) and then set up a Support File Search Path pointing to this location. To do this type OPTIONS in AutoCAD. On the files tab select Add and browse to the location where you saved your hatch patterns.
Once this file path is set up you will then have access to your new hatch patterns from within the hatch command.