A Quartz Block is a solid block in the game Minecraft made from Quartz, a mineral found in the Nether dimension. It is primarily used for building and decoration due to its smooth texture and bright appearance. Players can craft Quartz Blocks by combining four pieces of Quartz in a crafting table. In addition to its aesthetic appeal, Quartz Blocks are also used in various redstone contraptions and can be found in different forms, such as Chiseled Quartz Block and Pillar Quartz Block. These variations allow players to create diverse designs and structures in their Minecraft worlds.