Polo G Memorializes Late Friend BMoney with iPhone Chain & Pendant

Polo G is looking to set the trend of "smart jewelry" -- the Chicago rap star's cashing out for a diamond-encrusted bulldog that's plenty flashy, but also functional ... as an iPhone case!!!

Skylar Langfeldt of Icebox Diamonds & Watches tells TMZ Hip Hop the pendant took a couple of months of engineering to perfect all the features. For instance, Polo's phone can actually be charged without being removed from the sparkling accessory.

We're told the pendant includes more than 500 grams of 14kt white gold with 90+ carats of diamonds -- and there's another 55 carats of bling on the accompanying chain!

Fans might confuse Polo for a Boston Red Sox fan after seeing the chain and pendant's red letter "B" enamel accents -- but we're told it's actually a tribute to BMoney 1300 ... Polo's friend who was murdered in August 2021.