How does granite become quartzite?

Only indirectly. First you have to strongly weather the granite to form quartz and clays. Then you need to erode this material and separate out the quartz sand. read more

Granite is an igneous rock, while quartzite is a metamorphic rock; thus they both have different by origin and formation. They both are geologically different with different and distinct properties and due to this quartzite can never be formed from granite or vice-versa. read more

Granite becomes broken down by weathering so much it becomes particles, then gets washed downstream. Then, it deposits and turns to sandstone. read more

Granite found on the surface of the planet is subjected to different weathering agents. Wind, water and ice can cause the breakdown of granite into tiny particles known as sediment. The granite sediments are then carried by the same agents to other places, usually the bottom of water bodies. read more