Rerolling terror zone rare jewels

Just rerolled a level 42 rare jewel I found from a

Terror zone and it actually went UP to level 49. First time seeing a jewel level increase like that. Has this always been the case (and just extremely rare), or is this new with

Terror zone jewels?

The level you see on the jewel is the level requirement, not the item level.

An ilvl 95 jewel may well have a lvl requirement of say 19 because the affixes are all low lvl ones. If you reroll that and get a single affix with a lvl req higher than 19, the resulting lvl requirement will also be higher, moving up to that of the higher affix. That doesn't mean the item level has increased though.

Works as well on anything you reroll similarly, like charms.

I have a

Terror zone GC that I kept for rerolling - it gave me already something like +10 to life which has a level requirement below 10, and then ended up being a (low, unfortunately!) skiller.

Thanks guys, I guess I just never saw the level requirement increase before like that and thought it was something new. Rerolled many 49 and 42 jewels and every time before, they'd drop to lower lvl req. Guess that just shows how rare the 49 affixes are.