I totally and completely encourage you to research any area in which you want to set a Warriors work and determine or approximate what rocks and minerals predominate in your setting. However, if you don’t want to do that (because it is a lot of work and can get quite technical) or can’t (because you’re using a fantasy setting) I have provided these generalized rock prefixes to be used in lieu of detailed data, applicable to all regions.

Boulder- dark brown, or brown tabby with darker stripes

Rock- brown of any shade, or brown tabby with lighter stripes

Stone- gray or gray tabby of any shade