Nether Quartz is a type of material that can only be found in the Nether and is obtained by mining Nether quartz ore. They can be crafted into a block of quartz for decoration purposes and also can be crafted, together with glass and wooden slabs, into a daylight sensor, or into a redstone comparator with redstone torches and stone. Daylight sensors and redstone comparators are both used to send redstone signals.