Hailey Baldwin showed off her massive diamond sparkler from Justin Bieber on the cover of Vogue Mexico

Hailey Baldwin‘s gorgeous diamond sparkler from fiancé Justin Bieber just made its debut on a major magazine cover.

The 21-year-old model gave fans one glimpse of her oval engagement ring from Bieber, 24, on Instagram earlier this week, and now Baldwin’s flaunting her massive diamond on the cover of Vogue Mexico’s September Issue.

Bieber turned to Jack Solow, a private jeweler based at New York City’s family-run jewelry store Solow & Co, to design Baldwin’s custom diamond ring, which is somewhere between 6 to 10 carats.

“Justin did have a hand in selecting the diamond because I sent videos to his team,” Solow told PEOPLE. “I know him through [his manager] Scooter Braun. When it came time to find a ring, Justin asked Scooter and said, ‘I’m ready to pop the question’ and he said, ‘There is only one place to go, ask Jack.’”

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“In the end, Justin wanted something that would gracefully accentuate Hailey’s beautifully shaped hands. We settled on an oval stone that was just exceptional in its length and grace. Look at her hands — she’s exquisite,” says the jeweler, who had a “few weeks” to make the ring.

Solow added, “Justin gave this a lot of thought. When I saw him, I think he was very happy about what we did together. He was in a very good head space for the decision he was making.”

“I showed him all the details and all the intricacies like I would give any other 25-year-old boy who would come to the office to buy an engagement ring,” he said. “He seemed really excited. He was looking inside the diamond with the [jeweler’s] loupe, and said, ‘I think I see Hailey’s face.’”

The couple got engaged during a romantic vacation to the Bahamas on July 7 and confirmed the exciting news on social media two days after the proposal.

“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!” Bieber wrote in the caption. “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.”

Justin Bieber plays around making Hailey Baldwin laugh as they go to see a movie in New York
Credit: Splash News

While the whirlwind engagement shocked fans, sources have told PEOPLE the pair’s relationship is the real deal.

“This is not a joke to him. He proposed because he truly feels Hailey is the love of his life,” another insider told PEOPLE shortly after the July proposal. “He had a rough time last year, but he worked very hard to change and find more meaning in his life. Hailey couldn’t make him happier.”

EXCLUSIVE: Justin Bieber and Hailey Baldwin Reunite in Ontario Canada
Credit: The Image Direct

A Bieber source recently told PEOPLE the pair is slowing down their wedding planning so they can enjoy their engagement. The insider explained, “They still don’t want a long engagement, but they are also not rushing the wedding.”

“It was getting quite intense and they realized they want to enjoy being engaged for a while,” the source said of the pair’s engagement. “It’s not like they need to rush — they are both so young. They aren’t slowing things down though because they are unsure if they want to marry; they definitely want to get married.”