Medieval Jesuit Ring

A bit unusual because of the enameling. A type of niello ?

Wondering if it is an Jesuit ring and if there are any clues about the age of it.
Not much help with the location, it was the most random find at a flea market. No clue how it ended up at an Austrian flea market. Central european by the looks of it,if I were to guess.

 

Nice find, especially with the black enamel. Looks like a Medieval or Renaissance ring with a Christogram.
These were already made in Europe before the Jesuit order was founded in the 16th century, so no reason why there should be a specific Jesuit link.
This version of the Christogram, the IHS, dates back to the 7th century.

The photos aren't very clear, but it seems the enamel is in pretty good condition, whereas the bronze is covered in verdigris. I wonder if the enamel was applied later, maybe to make the IHS stand out more.

These ended up all over Europe, so why not at an Austrian flea market.