Golden State Warriors -- Secret Baller Feature On Championship Rings

The Warriors NBA championship ring has 240 flawless diamonds and almost 1/4 lb. in gold ... but the ring's most badass feature? DIAMONDS that GLOW under black light!!

Jason of Beverly Hills -- jeweler to 250 current NBA players -- tells TMZ Sports the "minimalist" ring has 10 hidden design features ("the inside of the ring is engraved to look like the Oracle Arena rafters") ... but the fluorescent diamonds are most impressive.

"Every diamond fluoresces," Jason told us, "We had to sort each diamond and pick flawless stones that barely fluoresced, with the exception of 4 that fluoresced bright white, almost blue."

Jason says examining the diamonds took 10 to 12 hours per ring. "We literally had guys in our factory in sleeping bags, sorting diamonds."

The glowing diamonds were strategically set at the bottom of the ring ... representing the organizations 4 NBA titles.

The finished product is awesome ... but Jason says he can't take all the credit for the ring ... "I got a good amount of input from the players, especially Steph Curry, Draymond Green, and Andre Iguodala."

#GlowingDiamonds #Swag