Drop/Place enchanted beacon, remember when pickup

Hello,
I am currently writing a Bukkit Plugin (1.8) which deals with enchanted beacons.
I want that the player can drop enchanted beacons and pick them up (when destroyed).
If the player picks up an 'enchanted beacon' there should be an enchanted beacon and not a normal beacon in the players inventory.

I have no problem with creating an enchanted beacon in the player's inventory.

Code:

ItemStack enchantedBeacon = new ItemStack(Material.BEACON, 1);
ItemMeta metaData = enchantedBeacon.getItemMeta();
metaData.addEnchant(Enchantment.DURABILITY, 1, true);
enchantedBeacon.setItemMeta(metaData);

If the player drops an enchanted beacon and it is placed in the world, I will be informed by the event onBlockPlace and save the information that the block is based on an enchanted beacon (and not on a normal beacon).

Code:

@EventHandler
    public void onBlockPlace(BlockPlaceEvent event) {

    Block block = event.getBlockPlaced();
    ItemStack stack = event.getItemInHand();

    if (block.getType() == Material.BEACON && stack.hasItemMeta()) {
    ItemMeta metaData = stack.getItemMeta();
    if (metaData.hasEnchant(...
   
    //block... Save somehow that this Block is based on an enchanted beacon

Now my problem:

If the block (marked as an enchanted beacon) is destroyed and spawned as itemstack in the world then of course the beacon is no longer enchanted.

If I want to convert it back into an enchanted beacon, I have to know whether the original block was marked as enchanted or not.

So, when the spawned itemstack is picked up by a player, how can I find out that it results from an enchanted beacon block?

Code:

@EventHandler
    public void onPickup(PlayerPickupItemEvent event) {
    Item item = event.getItem();
    ItemStack stack = item.getItemStack();
    Material material = stack.getType();

    if (material == Material.BEACON) {
        //How can I find out that stack results from an 'enchanted beacon block' ?

 

use setMetaData() on block.
and on break use getMetaData() from block
So u would get some keys, which u can transform with some brain to new enchantment from string