Isaiah Crowell Honors First Jets Season With Custom $50k Diamond Pendant

Isaiah Crowell ain't about to forget his first season with the Jets anytime soon ... 'cause the RB got a custom diamond pendant made to remember it forever!!!

TMZ Sports has learned the Jets star hit up Luxe Jewelers in Atlanta to make him some sick ice that commemorated his first year in NY ... and seems they delivered.

The drip -- which features Isaiah's No. 20 jersey and "Crow" nickname -- cost roughly $50,000 and has 12ct diamonds AND 150 grams of solid gold.

We're told the piece -- made by Ali G and Ali L -- has diamonds that are all VS clarity ... with a pendant that has 2 tones and is 3D.

Crowell had been having a solid first year with New York -- logging 685 rushing yards and 6 touchdowns -- before a foot injury ended his season a couple weeks ago.