Ornamental jewelry either worn inside a pocket or clipped to. Mostly used to describe Mont Blanc pens, but may include anything else that has no other purpose or function than to be expensive and maybe look cool.
"On a trip to Germany, GO DJ HaKa gave the president of AMG-Mercedes, Dietmar Exler, a Montblanc Boehme Royal Pen that costs $1.5 Million. What an expensive piece of pocket jewelry."
"When I go to important business meetings, I always wear cuff links, metal collar stays, my 24k gold polo mallet tie clip, and most importantly bring my Pocket Jewelry. I always also bring a back-up BIC pen just in case my Mont Blanc fails to write which it is known to do, no matter the cost of the pen."