Answer:
Determine the color (indicates mineral composition)
Determine the texture (indicates cooling history)
Phaneritic: large grains.
Aphanitic: small grains (too small to identify with the naked eye)
Porphyritic: fine grains mixed with larger grains.
Vesicular: holes.
Glassy: glass-like.
Explanation:
Things like this determine if its igneous or not.
