Anti-Magic Pendants

One of the more rare and interesting oddities of our modern day is the so-called "anti-magical" pendant (which, by the way, is not always a pendant in form, and can be, generally, any shape). The advent of these objects can be traced back just 68 years to 1051 AC to the dragonborn inventor Urbahg Felclaw Sabahgsson, one of the brightest minds of the Enclave of Arcanists at the time. His first prototype was debuted to the King of Nörn himself, and the royal court put in orders for several hundred pendants, so amazed were they by the device.
Functionally, the pendant is quite a work of magical art. As I understand it, the first step in creating a pendant is to acquire the required amount of refined umbor, a difficult-to-obtain metal with a very cost and labor-intensive extraction process. Once the desired amount is retrieved, the caster must "activate" it, and it will begin acting as a "sponge" for the energy of the River. The amount of umbor activated determines the size of this "bubble." Any spell or effect that draws upon the River's magic that crosses the boundary of the bubble is reduced in power according to the strength of the purification field -- which is derived from the purity of the umbor and the skill of the enchanter. The highest reduction thus far achieved by master arcanists following in Felclaw's footsteps (he passed only five years after his creation, his father watch over his soul) is 99.72%. Any reduction under this can be achieved, with the weakest pendants usually around a half-reduction, as a fifty-percent reduction is trivial to attain with even the least pure umbor sample.
Uses for pendants range widely from personal protection to edge-of-the-world exploration. Most wealthy families have at least some mid-to-high quality activated umbor relics, either for show or for personal protection. More active uses are those relics used in magical prisons, or those used by seafaring explorers who venture near the edge of our world -- the maelstroms there are so magically extraordinary that even non-magic users are given headaches in their proximity. The largest consumers of activated umbor artifacts are the magical enclaves, especially the necromantic enclave, which issues anti-magical staves to its purger squadrons. 
To acquire an anti-magical pendant, I recommend putting in a request with your local enchanter. Most certified enchanters have had at least some training in activating umbor, and even if they cannot fulfill your requirements, they will know someone who can. For the novice spellcaster, a low-reduction pendant is actually quite useful for practicing endurance during spellcasting. For protective purposes, a 75% reduction in spell-power crossing the boundary, unless pairing it with other enchanted arms and armor, is the bare minimum reduction to have even a chance at surviving combat spells. If you are looking to maintain or even activate your own umbor equipment, I recommend enrolling as an apprentice at your local enchanter's enclave (though not one of the major enclaves to date, they are still just as respected as the druids or the arcanists). The education you can receive from the enchanters is of the highest quality -- you will receive knowledge of many minor enchantments, along with the ability to activate umbor -- and can make you some decent coin besides.

Utility

Example Uses:

• Avoiding magical detection.
• Exploring the edges of the world near the maelstroms.
• Preventing criminals from wielding magic while imprisoned.
• Weakening demons, undead, rogue celestials, or other magic mal-users.
• Personal battlefield protection.
• Building endurance in novice spellcasters.

Inventor(s)

Urbahg Felclaw Sabahgsson

Complexity

The actual science behind the pendant is incredibly complex, much too complex for our chronicle. I advise reading the research notes published by the Arcanists from Urbahg Felclaw to learn more.