Cristiano Ronaldo's Fiancée Flaunts 30-Carat Diamond Ring in Venice

Georgina Rodríguez turned Venice into her personal jewelry runway -- and yes, she made sure to flash THE rock Cristiano Ronaldo gave her.

The recently engaged model walked the red carpet at the Venice International Film Festival in a beautiful black gown ... though the shine from her massive rings almost certainly grabbed the attention of everyone in attendance.

Check it out ... Rodriguez is sporting no less than four massive rings on her hands in these pics -- complimenting the jewelry with a choker and earrings.

Of course, the engagement ring she just got from Ronaldo sits among the others ... though it's not even the biggest one she's wearing.

But, it's probably the priciest ... 'cause reports indicate Ronaldo spent more than $5 million on this piece of jewelry for his lady love.

As you know ... CR popped the question earlier this month -- with Rodriguez sharing the news on her Instagram with a sweet photo of the amazing ring.

She captioned the pic, "Yes I do. In this and in all my lives."

Ronaldo and Rodriguez have been together since 2016 ... and Cristiano previously said it was only a matter of when -- not if -- they'd get engaged.