Sandstone and slate which quality is better
but without weathering sandstone, what metal can be polished on it, the hardness is high, but between the particles
Sandstone grading a lot, the surface of the red clay, red sandstone is after hundreds of millions of years of weathering
If it is volcanic ash sedimentary rocks, and deposition time has been hundreds of millions of years, certainly not bad.
Sandstone and slate are all sedimentary rocks, different regions, different quality
There are many kinds of slate, muddy, sandy, mixed quality.
