How to Make a Nether Portal in Minecraft. Two Methods:Using a Diamond PickaxeBuilding a Portal with a MoldCommunity Q&A. Nether Portals are used to transport yourself to the Nether in Minecraft. The portals are created from obsidian, one of the most difficult materials to mine in the game. If you have a Diamond Pickaxe, you can mine the obsidian and build the portal. If you don't have access to a Diamond Pickaxe, you can use a mold to create a portal structure without doing any mining. Nether Portals are available in all versions of Minecraft.