I tried to pick up more Treasure Keys and they did not show up in my Inventory or Postmaster.
After the House of Wolves launch, you'll find Treasure Keys while playing Destiny.
However, there are some special tidbits you may or may not know about the Treasure Keys:
- • Maximum stack size in your Inventory is 5
- • Maximum stack size in your Vault is 5
- • If your Inventory stack is full, any additional keys may not go to the Postmaster
- • You are guaranteed (1) key from Petra in the reef, when turning in your first bounty after weekly reset.