Extract Materia?

What exactly is this function supposed to do? I thought it was supposed to place a random materia in your inventory like the old Convert did except now it resets your spiritbond to 0% instead of destroying the item but when I use Extract Materia it resets the item's spiritbond to 0% but nothing else seems to happen. I don't have any new items in my inventory, and nothing is indicated in the chat log. Am I missing something or doing something incorrectly, or is it just bugged for me?

When an item is at 100% Spiritbond and you use Extract Materia you should:
1. Receive one new materia
2. See the Spiritbond reset to 1%

Ah! Okay, I think it was adding materia to stacks I already had so it looked like I wasn't receiving any new items, and I probably turned that chat log message off at some point so it looked like nothing was happening at all. But I can confirm now that it is indeed working. :p Thanks!