The first rock you come across appears to be black in color. It seems to have different layers and chunks visible throughout the rock. It is almost like you can see how the rock was formed over time with each layer linking to the next. It appears that you have discovered a sedimentary rock known at coal!
As you are walking along you come across another sedimentary rock! Wow! This rock is definitely sedimentary because it is almost like the sediments are falling off as you touch it! It feels grainy, and you can see the layers again! This rock is called sandstone! Can you guess why?