Minecraft wiki entry for How_to_play, associated text: Glass - This is a transparent block that is made by smelting sand in a furnace.
Concrete - This is made by dropping a concrete powder block into water.
Terracotta - This is found naturally in mesa biomes or can be crafted and dyed from clay that is found underwater. Terracotta can be made into glazed terracotta by smelting it in a furnace.
Magma - This is found naturally in the Nether, it emits a little light and burns whoever steps on it.
Coarse dirt - This is almost like a normal dirt block but grass can't grow on it. It can be found in savanna and mega taiga biomes.