@EventHandler
    public void onPreItemCraft(PrepareItemCraftEvent e) {
        Recipe craft = e.getRecipe();
        if (craft==null) return;
        ItemStack result = craft.getResult();
        if (result==null || result.getType()!=Material.QUARTZ_BLOCK) return;
        ShapedRecipe shapedCraft = (ShapedRecipe) craft;
        if (shapedCraft.getIngredientMap().size()==4) {
            e.getInventory().setResult(null);
        }
    }