Young M.A Drops $140k on Birthday Bling For Herself

Young M.A is treating herself for her upcoming birthday ... throwing down fat stacks of cash for some insane custom jewelry that's guaranteed to outshine any of her other presents!!!

We've learned the "OOOUUU" rapper dropped a whopping $140,000 on a diamond chain and pendant ... hitting up Ali G and Ali L over at Luxe Jewelers in Atlanta for the super sick piece.

The specs on the bling are pretty wild ... we're talking more than 39 carats of diamonds, with the pendant and bussdown cuban link chain tipping the scale at 129 grams.

We're told Young M.A scooped up the jewelry on Wednesday, which is a week before her 27th birthday. If you're looking for a last-minute gift, may we suggest a turtleneck ... she's gonna need it for all that ice on her collar!