500
(This one is also a regular question...no need to answer it with "What is...")
If an extrusive and intrusive rock contain the same minerals, why would they look different. And how would they look different?
1. they would look different because the EXTRUSIVE rock cooled much FASTER when it was made. The INTRUSIVE rock (and the minerals inside), cooled SLOWER.
2. they would look different because the intrusive rock would have time to form large crystals. The extrusive one would probably not have crystals (since it cooled so quickly).