The occurrence of quartz in high amounts makes a rock

A. Acidic

B. Alkaline

C. Neutral

D. None of these

Answer: Option A

Solution(By Examveda Team)

The occurrence of quartz in high amounts makes a rock Acidic.
Rocks are referred to as acidic if they contain more than 20% of free quartz. It is based on the idea that high silica rocks are acidic whereas the rocks with low silica content are basic.
Typical acidic rocks are granite or rhyolite.