Will You Marry Me? Great, Now Choose One of These Six Rings

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When it comes to getting engaged, most brides report that their men got down on bended knee and produced a diamond ring to profess their enduring love.

But what if Mr. Hopeful displayed six different mock rings—sterling silver rather than gold, cubic zirconia instead of diamond—and said, "Pick one, sweetheart"?

Ocappi, an online diamond company that will announce its launch Wednesday in New York, aims to equip that man with those rings. Each ring will require a $75 deposit and must be returned within five days.

"It's time to bring new technology and an appreciation for convenience, like Warby Parker is doing for eyewear, to what is too often an intimidating experience," Ocappi CEO Isaac Gurary said in a statement. Gurary, whose Russian immigrant grandfather started working in the diamond industry in 1956, received a $10 million private investment to launch the business.

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Unlike Warby Parker, whose business model is to sell cheaper glasses by cutting out the middle man, Ocappi tends toward pricier engagement rings, between $5,000 and $45,000.

Mary Mack, a freelance writer in Newport, R.I., said something like Ocappi's "One&Only Try-On Service" might have suited her when she got engaged in 2009.

"We had gone to normal jewelry stores, but the prices were really high, and you feel cheap when you walk in and are face-to-face with the clerk and tell them you're looking for the best deal," Mack said. "When you're just Google shopping, no one is judging."

Mack wouldn't be a likely Ocappi customer, however, as she found her engagement ring for $600 at Amazon. She sent the link to her then-boyfriend who made the purchase. (He bought his Tungsten wedding band for $35 on Amazon.)

But Mack advises subtlety. "Definitely don't show up with six rings to the proposal," she said.

Mack and her husband are unusual: A survey by The Knot, the wedding industry's largest online bridal site, found that 9 percent of grooms bought their fiances' engagement rings online. (The proposal remains a gendered institution; The Knot found that just 1 percent of women proposed.)

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Ocappi aims to wedge into the $11 billion annual wedding industry by capitalizing on anxious men who don't know which ring to pick. Clueless, perhaps, but nearly all end up buying diamond rings. Among brides surveyed by The Knot, 93 percent said they sport diamond rings averaging $5,200.

Ocappi's model resembles Blue Nile, an online jeweler based in Seattle, where rings average $6,000. Blue Nile was founded in 1999; today, diamond engagement rings make up about 70 percent of its business. The company boasts an inventory of 100,000 stones.

In a statement, Ocappi referred to Blue Nile's "sprawling selection," saying it's too confusing. Tiffany & Co., Ocappi said, is too intimidating.

Reached Monday, Blue Nile spokesman Josh Holland said that Blue Nile doesn't need to send replicas to customers, noting that fewer than 10 percent of customers return or exchange their rings. (Blue Nile has a no-questions-asked, 30-day return policy.)

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"We don't have to rely on mock-up play rings," Holland said. "Sending something with CZ doesn't educate the customer—they still don't know what they're getting."

He said Blue Nile's "stellar photography" provides grooms with an accurate idea of what the ring would look like. Grooms nervous about sizing receive a plastic ring-sizer to match against their girlfriends' existing rings.

But Ocappi believes the grooms will come, even though survey figures from The Knot suggest that men, overall, do well choosing rings. About 95 percent of brides reported loving their rings, and those who said would have chosen something different added that they loved or "learned to love" what their guy chose.