A. A single variation can be beneficial under some conditions and harmful under other conditions
1- Classified by texture and composition
2- Rarely has fossils
3- May have alternative bands of light and dark minerals
4- May react with acid
5- May be composed of only one mineral , ex . Quartzite
6- May have layers of visible crystals
7- Usually made of mineral crystals of different sizes
8- Rarely has pores or openings
9- May have bent or curved foliation
You lucky because I learn this last week so .... I hope that's enough for your question and I hope I really help ! Good night my friend
Since they have been there for a long time, they have become coarsely!
Hope I helped! Just tell me if i'm wrong!
The process is called Condensation
