Nether quartz is an item added in the 0.6.0 update. It is spawned by the Nether Reactor (or Nether Machine) in large quantities and is used to craft Block of Quartz. Nether quartz can also be used for crafting Granite and Diorite.
Trivia
- Quartz was added to PE before it was added to PC.
- It takes only 4 nether quartz to make a block of quartz.