Battle of the bling! Ariana Grande and Hailey Baldwin are both rocking huge engagement rings these days after both ladies said yes to two very whirlwind proposals — Ariana's fiancé Pete Davidson popped the question after a few weeks of dating and Hailey's fiancé Justin Bieber proposed one month after they rekindled their romance. Both rings are absolutely gorgeous, but they're also both very different, so gemologist and diamond expert Grant Mobley chatted exclusively with Life & Style to reveal details about each ring and he also helped us decide which diamond sparkler is the better ring!

"Ariana's ring is a three-carat pear-shaped diamond which I think is an awesome shape for her specifically, it just seems to fit her really really well," Grant explained. "It was purchased by Pete from a guy here close to my office called Mr. Flawless. I know that they focus a lot on very high-quality so the ring is very high color and clarity which is why that it was about a $100,000 ring — and that’s because the color, clarity, and size all combined."

ariana grande hailey baldwin engagement rings

(Photo credit: Getty Images, Splash)

Grant went on to explain that Ari's ring is set in a custom-made mounting with a halo of diamonds around the center stone, and just for an extra touch, there are more diamonds going down the shank. "I think it’s just such an amazing ring, very perfect for her. And [Pete] didn’t go too crazy with it, it’s not some super trendy crazy thing that’s gonna go out of fashion. It’s very classic, very simple, and it’s just gonna last forever. there’s no question about that. It’s never going to go out of style."

Hailey's ring, on the other hand, is a lot bigger but a little bit more simple — a stunning eight-carat oval-shaped solitaire, which is a very popular shape at the moment.

"I absolutely love the shape. The great thing about the oval shape is it tends to look larger on the finger — and that’s because an oval is an elongated brilliant cut as opposed to a round or a cushion cut," Grant explained. "So when you make the cut elongated, it kind of gives it an optical illusion that the stone is larger than it really is."

grant mobley diamond expert

(Photo credit: Grant Mobley)

Now, of course, since Justin Bieber is a huge pop star, he can definitely afford to buy a large diamond regardless of shape or cut — and Grant says he must have spent at least $600,000 on Hailey's bling. So when celebrities are choosing engagement rings, it's more about comfort and personality and style. Justin must have either done his research or got some major hints from Hailey because Grant said he ended up choosing a shape that is the most comfortable to wear.

"It looks more natural on the finger, especially if you’re going to go with a large stone, it just follows your finger a little," Grant continued.

Of course, both rings are absolutely stunning and they both fit the personalities of the wearer very well, but Grant revealed which one he thinks is the best — according to his personal, expert opinion.

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Was gonna wait a while to say anything but word travels fast, listen plain and simple Hailey I am soooo in love with everything about you! So committed to spending my life getting to know every single part of you loving you patiently and kindLY. I promise to lead our family with honor and integrity letting Jesus through his Holy Spirit guide us in everything we do and every decision we make. My heart is COMPLETELY and FULLY YOURS and I will ALWAYS put you first! You are the love of my life Hailey Baldwin and I wouldn’t want to spend it with anybody else. You make me so much better and we compliment eachother so well!! Can’t wait for the best season of life yet!. It’s funny because now with you everything seems to make sense! The thing I am most excited for is that my little brother and sister get to see another healthy stable marriage and look for the same!!! Gods timing really is literally perfect, we got engaged on the seventh day of the seventh month, the number seven is the number of spiritual perfection, it’s true GOOGLE IT! Isn’t that nuts? By the way I didn’t plan that, anyways My goodness does feel good to have our future secured! WERE GONNA BE BETTER AT 70 BABY HERE WE GO! “He who finds a wife finds a good thing and obtains FAVOR from the Lord!” This is the year of favor!!!!

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"It’s really hard to say when you’re dealing with two rings that are very very simple like this. [Hailey's] is just a solitaire — which is the stone by itself," he said. "But then, Ariana’s has the halo which is also very, very classic and simple, but it was just a little bit extra. At that point, for me, I would have to say Hailey’s because I am a little bit more partial to oval and it’s also a bigger stone so I’m all about the size." Well, there you have it!