If you're Inventory >> Consumables tab is full and you turn in the Petra bounty for the offering to the oracle, it will disappear. I'm fully aware that it's my fault for not being more cautious of my inventory but if it was like ANY OTHER Consumable it would've been sent to the postmaster - but instead it just gets deleted. Bungie, either give us the offering back, inventory or postmaster, or let us do the bounty again. Thanks for listening guardians.