Quartz

Quartz is a raw material used primarily to get Clear Glass. It is found by mining Sand, at a 5% chance of replacing the dropped Sand block. It is stackable, with each stack having a maximum quantity of 64 Quartz.

Uses
When smelted in a Furnace, it yields 1 block of Clear Glass.

As a Brewing ingredient, it will turn an Awkward Potion into a Potion of Clear Sight, which in turn, when corrupted with a Fermented Spider Eye, will turn into a Potion of Blindness.

Farming
Quartz can be farmed from Sand by using a Sieve, which also creates Sand Powder.

Trivia

 * Sand mined with a Silk Touch enchanted tool can never turn into Quartz.