Render Block Basic

Rendering a basic block is very similar to a basic item except that you need two JSON files now. One for the blockstates:

SimpleTexturedBlock.java

public class SimpleTexturedBlock extends Block {

    public SimpleTexturedBlock() {
        super(Material.ROCK);
        setUnlocalizedName(ModTut.MODID + ".simpletexturedblock");
        setRegistryName("simpletexturedblock");
    }

    @SideOnly(Side.CLIENT)
    public void initModel() {
        ModelLoader.setCustomModelResourceLocation(Item.getItemFromBlock(this), 0, new ModelResourceLocation(getRegistryName(), "inventory"));
    }
}

Now the blockstate JSON (resources/assets/firstmod/blockstates/simpletexturedblock.json): (Please note that simpletexturedblock.json is the exact same name as the name set in your unlocalizedName and RegistryName above!)

resources/assets/firstmod/blockstates/simpletexturedblock.json

{
  "forge_marker": 1,
  "defaults": {
    "model": "modtut:simpletexturedblock"
  },
  "variants": {
    "normal": [{}],
    "inventory": [{}]
  }
}

The model itself (resources/assets/firstmod/models/block/simpletexturedblock.json): (Please note that simpletexturedblock.json is the exact same name as the name set in your unlocalizedName and RegistryName above!)

resources/assets/firstmod/models/block/simpletexturedblock.json

{
  "parent": "block/cube_all",
  "textures": {
    "all": "modtut:blocks/blocktexture"
  }
}

Then don't forget to add a blocktexture.png texture in assets/firstmod/textures/blocks