I need help identifying if a rock is igneous, sedimentary or metamorphic.

Question

I just need help identifying if a rock is igneous, sedimentary or metamorphic. The merlot rock (the one on the top left) is smooth and the rest feels kind of grainy.

Images of rocks: https://m.imgur.com/OSFj7Lw

Im not really good at identifying rocks and neither is my team. Basically I have to do all of this myself if I want a decent grade since the two other workers are basically freeloaders.

Answer 1

I have never heard of a merlot rock before. Be sure to check the name. Are you trying to describe the color? Color can be helpful but is the least reliable property. You also need to add more details to correctly identify this rock. Smooth is one characteristic, but all three categories of rock can be smooth. My best guess is that it's a sedimentary rock, most likely siltstone on account of its smoothness and reddish brown color.