You suspect that a rock you have found is sedimentary rock. what features would you look for to confirm your identification?

Look for grains cemented together, they can usually be rubbed off easily. It's easily friable and layered due to deposition. It's earthy so it'd be pretty dull and have no crystals whatsoever. etc. 

Answerseafloor spreading;

Answer (d) may increase or decrease porosity through dissolution or deposition;