Can Contingency be used with a spell cast from an Ioun Stone?

Contingency says:

Choose a spell of 5th level or lower that you can cast, that has a casting time of 1 action, and that can target you. You cast that spell–called the contingent spell–as part of casting contingency, expending spell slots for both, but the contingent spell does not come into effect.

Would one be able to use a spell that is cast from a Reserve Ioun Stone as the contingent spell?

For example: A bard casts revivify into the Reserve Ioun Stone and gives it to the wizard who then uses contingency along with the stored revivify to create an effect that would revive him upon falling unconscious. The wizard cannot cast revivify normally.

Would this work?

My specific concerns are:

  1. Does having the spell stored in such a way count as a spell “you can cast”?
  2. Does the fact that the spell is stored in an item mean that it can’t be cast as part of another spell as contingency requires?
  3. Is there any other reason why this would not work?