Stassi Schroeder's Engagement Ring Is a 1900s Heirloom 'Straight Out of Downton Abbey'

When Vanderpump Rules star Stassi Schroeder‘s boyfriend of about two years, Beau Clark, dropped down onto one knee to pop the question in the middle of a cemetery on Wednesday, he held a fake urn in his hand — with an antique diamond sparkler nestled inside.

Speaking exclusively to PEOPLE, the newly engaged couple revealed that Clark proposed with a family heirloom from the early 1900s. The 3.5-carat ring features one large European round-cut diamond surrounded by 24 smaller stones in a platinum setting. Clark’s grandfather acquired the stunning piece in the 1940s or ’50s, he says, and it was passed down to his aunt.

Schroeder, 31, says it feels like wearing a piece of history on her finger. “It’s beautiful. I feel like it’s like Cinderella’s glass slipper or something in a ring. It’s like, straight out of Downton Abbey,” she gushes. “I’ve never really been someone who’s dreamt of my engagement ring, because I love all jewelry … any stone, any shape. Beau kind of asked me, ‘What do you like?’ I’m like, ‘I kind of like everything. I know that doesn’t help, but I feel like you’ll make a good decision. Whatever you think is representative of us. I think that you’ll make the right choice.’ So I knew no matter what I would love it. But I never thought I would get something like this awesome and big.”

RELATED: Vanderpump Rules Stars Congratulate Stassi Schroeder on Her Engagement to Boyfriend Beau Clark

And she admittedly can’t stop staring at her hand. “I feel like an a–hole,” she says. “Like, I’m just turning into an a–hole the more it’s on my finger.”

Clark, 39, compared the ring to the mystical objects containing fragments of Voldemort’s soul in Harry Potter: “I keep calling it a horcrux, because she said like, the minute she put it on, she starts acting all weird. I’m like, ‘Switch hands, take it off. Let me hold it for a little bit.'”

“I know,” she says with a laugh. “I was like, ‘When I get engaged, I’m going to be so chill, I’m going to be a chill bride.’ Like, no. I feel myself transforming.”

But back to the proposal: Clark says he’d been planning on asking Schroeder to marry him since January, though he purposefully threw her off his trail by insisting he wouldn’t be ready this year. “He has been tricking me and torturing me for the past six months!” she says.

Originally, he’d tapped producer friend Randall Emmett (VPR star Lala Kent‘s fiancé) to help him find a production designer to build a fake mausoleum where he could propose. But when Schroeder suggested they actually tour the Hollywood Forever cemetery, “it was like God just laid it out on the table for me,” he says. “She’s going to have no idea.”

A friend guarded a ring box shaped like an urn near a bench by a pond, hiding as the couple approached on their stroll. Clark pretended to notice the “urn,” picked it up, turned to his girlfriend, and professed his love.

“I’m like, ‘If you think it’s an urn, you can’t pick this shit up,'” she recalls. “I don’t even remember the moment that I realized that it was happening.”

Why get engaged in a graveyard? As loyal fans of her reality show, podcast and book (Next Level Basic) well know, the New Orleans native has a penchant for the macabre. (See: her obsession with serial killers.)

“I like going to each grave and each tomb or mausoleum and reading the names and seeing the dates, and imagining who those people were, what their lives were like, what they were wearing, if they were bratty or fun, you know? If they liked to drink a lot of alcohol,” she explains. “I love history and whenever Beau and I go on trips, or go out of the country, he always takes me to a new cemetery. So I’ve seen so many different ones with him, and it just felt like just, I don’t know, just me. I love it. I don’t think it’s morbid. I think cemeteries are just full of so much love and history.”

RELATED VIDEO: Vanderpump Rules‘ Star Stassi Schroeder Engaged to Boyfriend Beau Clark

Next, the couple will embark on an 18-date tour across the country for her podcast, Straight Up with Stassi. And yes, they’re already thinking about wedding plans, fantasizing about a small ceremony in Italy, where the groom was raised.

And, no, she wouldn’t want to get hitched at a gravesite on Halloween.

“No, I think the spookiness ends with the engagement,” Schroeder says. ” I feel like I don’t want my weddings to be like, tacky.”