Like the Major and Minor Creation spells, Permanent Creation allows the wizard to pull wisps of material from the Plane of Shadow to create objects of vegetable and mineral nature. The difference is in the item's duration. Some, specifically the vegetable matter and the more mundane of minerals, will actually solidify and become permanent (so powerful is the binding energy of this spell):
Vegetable Matter -------------------------- Permanent
Stone or Crystal --------------------------- Permanent
Precious Metals --------------------------- 1 hour/level
Gems ----------------------------------------- 2 turns/level
*Mithral ------------------------------------- 1 turn/level
Adamantite --------------------------------- 2 rounds/level
* This includes similarly rare metals
Attempting to use any non-permanent creation as a spell component will cause the spell to fail. Permanent items may be used though, as they are considered real for all purposes.
Permanent items, once completely formed from their shadow stuff, are bound together and to this plane and are thus considered, as mentioned above, real for all purposes. They are also beyond the power of a Dispel magic to get rid of, though they would still cease to exist if they entered a dead magic zone or were faced with dispelling magic as powerful as a Mordenkainin's Disjunction or a Power Word, Cease.
The spellcaster must have a small amount of the item to be created, to use for the material component (wood to create a door, a chip of stone to form a boulder, ect.).