As of 2014, you can create glass in the PC version of Minecraft by smelting blocks of sand in a furnace. Glass is used as decorative features on houses and to make potion bottles.Continue Reading
Get sand blocks from a desert biome or near water by shoveling the resource. Take these sand blocks to a furnace.
Place up to 64 sand blocks in the upper block of a furnace, and put your fuel source in the bottom square. Coal is the most common fuel source you can use. Smelt up to eight blocks of sand with one piece of coal.
Produce 16 panes of glass by placing six blocks of glass in the bottom six squares of a crafting table to make thinner windows. Create a glass bottle to hold potions by arranging three blocks of glass in a "V" shape on a crafting table. Put dye in the middle block of a crafting table, and then surround it with eight blocks of glass to make stained glass. Craft a beacon with a Nether Star in the middle of a crafting table, surrounded by three blocks of obsidian beneath it and five blocks of glass in the remaining squares.
Once you break glass, it cannot be put back together unless you have silk touch on your weapons. Glass can hold back lava, water and hostile mobs unless you break it.