If the player is going to destroy or alter the tile you can file specifices in a dictionary with key 22d44 say for tile at 22,44 once the ore is destroyed erase the entry from the dictionary. If the player does lots of tiles halfway you might not want to use a dictionary, but if it is sparse matrix, so to speak, it will work fine.
If you need to know all kinds of things about the tile location store it as a string (even a json string).
yours
winkr7