http://en.wikipedia.org/wiki/Quartzite
both questions are answered in the first two paragraphs: streaks and rows are the same.
Q1: What rock comes before quartzite in the rock cycle? What rocks or rock could come just after quartzite in the rock cycle?
Q2: A geologist finds a course grained rock with crystals arranged in rows. What can the geologist infer about how this formed and what group it belongs to?
2 answers
igneous,sedimentary,metamorphic