Glass

Glass is a transparent block commonly placed as a window. When broken you will not get the block back.

Purpose
It currently has no other use than decoration or aesthetics.

Smelting
Glass is made by smelting sand in a furnace.

Glass Pane
Glass Panes are a smaller, thinner version of glass. They can be crafted with 6 pieces of glass. They are mostly used for windows in houses.

Crafting
6 Blocks of glass are required to craft 16 Glass panes.

Trivia

 * Glass is not flammable.