Jay Z hardly makes a big splash but rapper J. Cole will forever remember he once had the hip hop powerhouse perform for him on his birthday and then; also got his most precious jewellery of all time ... not his wife, silly!

According to TMZ, Jay Z pulled out all the tops on Tuesday night during rapper J. Cole’s birthday concert in New York, surprising the just turned 29 years old rapper with a spectacular guest performance before handing over a priceless piece of his rap history.

Reports say the crowd went gaga at the Madison Square Gardens when Hov jumped on stage to perform PSA for Cole, leaving the young rapper in total shock! But the most memorable moment came when the superstar [Jay Z] pointed at the diamond necklace on Cole’s neck and said, "it's yours".

According to reports, the diamond chain was Jay Z's original Roc-A-Fella bling from when he founded the label in the 90s.  J.Cole thought he was wearing the chain on loan for the night ... but Jay Z turned to him and said, "That, on your neck, is my original Roc chain -- and it's all yours." If this does not define legendary, then we don't know what the word really means! Awesome!