Where to find them
Most of the Crystal Caster Armors can be found in Aelerium. Since it is a region which has all types of Crystals all types of Caster Armors can be found here. The majority here are of the Cloudcrystal kind, especially around the capital city Infor. All of the other armors are created here as well although to a lesser degree.
The Embercrystal Armor however are more common in
Mervidel due to the large amount of Embercrystals there. In addition the Elves living there have included the crystals not only in their armor but in their weapons as well.

by Kefekjaco with Heroforge
Although it is not verified, many belief that the vast majority of Tremorcrystal Armors can be found in the
Lower Realms. This theory receives some credibility thanks to the discovery of these kinds of armor in ruins there.

by Kefkejaco with Heroforge
The largest amount of Seacrystals are found along the western Isles of Farlis and the Oneragan East coast. It took a long time for the techniques of making the armors to reach these regions. For this reason the amount of Seacrystal armors there is not as high as one would suspect. An additional limit on excavating these crystals is that many are found underwater.

by Kefkejaco with Heroforge
Chaos Crystals
There is one type of Caster Armor which is forbidden in every nation of Niorath, the Chaos Armors.
Many of the world's monsters and danger are blamed on use of Chaos magic which caused the nations to ban it's use once and for all. There are still some places however, mostly where people don't like to obey the law as much, where these type of armors can be found.
Since Aelerium has the best Crystalweavers one is most likely to find a Chaos Armor there. It is said that they are far more powerfull than regular Casting Armors.
Amélie I. S. Debruyne
Great article! I love how the armours send elemental magic attacks :D Is the crystal on the armour flexible? It seems to be one band of crystal from the illustrations :p I think you can add if its small bits sewn onto the robes to make them form a line. Are there some slight variations of colour between crystals of a same kind? Would some special taint be privileged over others? You don't have a mouse-hover snippet for under realms expedition. I like the history bit. Are crystals very resistant? Some real crystals can get damaged with shock or get dissolved by water or acids. Given their price, I'd imagine some people would not be very happy if something like that were to happen… Can they get damaged if used too much or too much magic is channel through them? Does time has any effect on it? Not a very necessary element but I'm wondering how the crystals are obtained. Are they mined? Has there been attempt at creating them artificially? Are they safe to mine? I like the idea of the pattern on the armour being used to identify the family.
Thanks Amélie! :) So yes they are flexible but only for those capable of using advanced magic. A small layer is sewn on the robes but the breastplate has larger crystals infused. But good idea to include a manufacturing section :) The crystals are actually very resistant but they can deplete over a very long time. Luckily for the user the ones in the armor are replenished by using magic. But for that entire part I am going to write an article that I should have made a long time ago but I always get sidetracked xp