I haven’t a clue. Worth testing, I suppose!
Edit: if you go on NWDB and look up a jewelry piece, then it says whether or not you can replace the gem. I do not know what decides whether or not you can replace the gem 
Maybe pre-Brimstone vs post-Brimstone jewelry?
Heart of Anhurawak - Item - New World Database ← it’s like a green or red check mark next to the gem description.
You are wrong. Have you played the game? Many items in NW come with exchangeable gems.
Examples:
And dozens of others.
Please do not spread misinformation. If you don’t know an answer to a question, don’t make things up.
He was just making that up, a lot of named jewelry has exchangeable slots. Pieces like the “illegal” thrust/keen ring wouldn’t be BiS without it.
However, to @STAR33’s initial point, it’s extremely inconsistent. Some named jewelry can be swapped, some can’t. Some post-Brimstone jewelry is exchangeable, others aren’t.
How many do you have? You seem well prepared to just use them and throw them away once they have fulfilled their goal.
Lmao do some people seriously not know this already
Nah you can swap gems on some named items
There is plenty of named jewelry where you can swap out the gems. So the question still remains: Why some but not others?
The gem should be able to be changed in all items. Period.
I see you have the whole team working on that holiday you promised 
What?
Are you asking how many named items I have in storage?
I seem “well prepared” to throw my own gear away? What are you even trying to say here?
I fail to see how any of that is relevant and not an attempt at redirecting from the deliberate misinformation you were caught spreading.
You’re making us a holiday? 
This has nothing to do with whether or not the gems are swappable. Many are.
Many do apparently. 1000+ hours and only 1 build to show for it, they must be throwing reasonably decent gear away.
How is that at all relevant to you trying to convince people that gems aren’t swappable?
Why do devs force us to not be able to replace a gem on crafted jewelry? 
Obviously for economy balance reasons, this is still an MMO.
yeah that too why we cant change gems on crafted jewel … you really think a gem is gonna change economy balance !! that’s some high iQ thinking there !! can you explain why or how it gonna affect economy?
Reinforced items can’t have their gemstones changed. Anything else is fine though, so I don’t see the problem.
New and/or financially-challenged players, especially those on fresh start servers, have very limited jewelry options for mage builds.
Even If you could take out gem you would only be able to put another fire gem(or non elemental) in due to fire damage perk