sedimentary rock: a form of fine-grained sandstone consisting of compressed silt. It is rather like shle, but a bit finer. I would think it might be to brittle for landscaping, would not hold up well.
Siltstone is a type of rock which is sedimentary. It is very fine in composition, more so than sandstone. It's majority is made of silt, and not clay like other popular landscaping rocks.
It is a sedimentary rock that is the size of a grain that is primarily comprised of silt rather than clay like other sedimentary rocks. It is finer than sandstone but not coarse as clay stones. It is often mistaken for shale but lacks the lamination that shale has and is not made from mud.
It's a natural quartz, thats very strong and durable. I know it makes beautiful walls and even for construction. So landscaping for a back yard should be no problem at all.
