Main plugin;

	  public OreRegen(Main instance)
	  {
	    this.plugin = instance;
	  }

	HashMap<Block, Location> blocky = new HashMap<Block, Location>();

	public void onBlockBreak(BlockBreakEvent event){

		final Block block = event.getBlock();
		final Location loc = block.getLocation();

		if(block.getType().toString().contains("ORE")){
			blocky.put(block, loc);

			plugin.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {

			    public void run() {
// right here is where I want to replace the block with what it was

			    }
			}, 60L);