Are Items Decided Before Identifying?

I've noticed that some unidentified wands stack, such as when a loot bomb is thrown, while others in the same level range do not stack. When I've identified the wands the ones that stack are the same wand, while the wands that didn't stack are not the same wand.

Note: the id's are different on wands that stack

 

When you throw unidentified weapons, their texture changes to the one you get after identifying so yes, they're decided before identifying.

 

Thanks.