Sand (Forge) is a material used by the Forge for crafting items from forge recipes. It does not exist as an actual item in the game.
Once a source of glass such as Broken Glass or Crushed Sand has been smelted in the forge, it becomes available as glass. The glass for a recipe must already be smelted in the forge before you can craft the recipe. For a complete understanding on how to smelt glass and other materials, see Smelting.
The following recipes require Glass (Forge): (NOTE: Times are based on a level 1 skill and the material that an object is crafted from, which is only reliable for food at the moment, so is rather difficult to calculate, this table is auto-generated):