Nether Quartz

Nether quartz or simply Quartz is a Nether exclusive item.

Obtaining
Nether quartz can be obtained by mining Nether quartz ore. In Pocket Edition is dropped as an item by the activated Nether Reactor.

Video
Note: The video does not show a crafting recipe for Granite and Diorite, this was before they were added in 1.8.