The entrepreneur and “Shark Tank” star will share his top tips for success.
Retailer Talk: Two tools that changed my year
Michigan retailer Randy Cole attended a trade show earlier this year where he found two products that, he says, changed his entire business model. One is a patented princess-cut diamond and the other is a machine that leaves its mark.

Troy, Mich.--Michigan retailer Randy Cole attended a trade show earlier this year where he found two products that, he says, changed his entire business model.
One was the FireMark, the patented princess-cut diamond from New York-based diamond company Hasenfeld-Stein Inc.
The other was Gemprint, a service offered by the Gem Certification and Assurance Lab, or GCAL, the New York laboratory run by Don Palmieri.
In a recent interview with National Jeweler, Cole, CEO of the Diamond Vault of Troy, broke down why these two tools, which he discovered at the Centurion Jewelry Show held in Scottsdale, Ariz. in February, are working for him, a jeweler whose business is heavily reliant on bridal.
Retailer Talk is a new feature for National Jeweler that allows jewelers to share the practices that are working in their stores or vent about the ones that aren’t.
1. Sales on Fire. Cole, admittedly, has never been a fan of princess-cut stones, even though they are the second most popular shape for engagement rings, trailing only the traditional round.
Cut for weight, princesses are, generally speaking, too deep, have a wide-open table and a low crown, resulting in poor light return and no prismatic color.
But this is not the case with the FireMark, he says. The diamond has a 98 percent average light return, compared with 80 percent for traditional princess, thanks to its higher double crown, smaller table and shallower depth.
“For me, selling a FireMark is the easiest thing I’ve ever done,” said the retailer.
Cole said after Centurion, Hasenfeld-Stein sent him two stones on memo. He sold both the same day, “And we haven’t stopped since,” he says, noting that they’ll sell as many as three in a single day.
The way he sells the diamond is this: he keeps a normal 0.70-carat princess-cut diamond on hand and compares it with a 0.60-carat FireMark princess cut. The FireMark is more brilliant and actually looks bigger, he says, making for an easy sale.
Another feature he likes about the FireMark may sound counter-intuitive to many retailers: Hasenfeld-Stein doesn’t offer jewelers any co-op.
While co-op is nice, Cole says the advertising gets built into the price of the goods, resulting in a higher cost for him and, ultimately, his customers. He’d rather market the diamonds himself and be able to keep his prices down.
Cole adds that he is not necessarily
But Cole said using trusted sources is adequate reassurance for him. “We do the Kimberley Process. That’s enough,” he says.
2. Leaving fingerprints. Gemprint shoots a non-damaging laser into a diamond, which creates a constellation-type reflection that’s unique to that stone. The registration of this reflection pattern allows the diamond to be positively identified if it’s lost or stolen, the same way that people can be identified by their fingerprints.
Cole shelled out $14,000 for the Gemprint machine at Centurion but he said it has been worth it, for the exclusivity alone.
“I am the only one in Michigan who has a machine,” he said, noting that another retailer actually pays him to Gemprint his stones for him.
He said the machine sits out in the open where customers can see the scanning process while their online registration is created.
“A customer’s biggest fear is that their stone may be switched at some point. Gemprint allows a positive identification even if it does not have a grading report,” he says.
As an added selling point, Cole says more than 20 insurance companies offer discounts to consumers on their annual personal jewelry insurance premium if their stone is registered with Gemprint.
Want to share a practice or product that is, or isn’t, working for your store? Email Editor-in-Chief Michelle Graff at michelle.graff@emeraldexpo.com.
The Latest

The Ukrainian brand’s new pendant is modeled after a traditional paska, a pastry often baked for Easter in Eastern European cultures.

The “Strong Like Mom” campaign features moms who work at Tiffany & Co. and their children.

Interior designer Athena Calderone looked to decor from the 1920s and 1930s when crafting her first fine jewelry collection.


During a call about its full-year results, CEO Efraim Grinberg discussed how the company is approaching the uncertainty surrounding tariffs.

The free program provides educational content for jewelry salespeople and enthusiasts to learn or refresh their diamond knowledge.

Bench jewelers spend years honing their skills, Jewelers of America’s Certification validates their talents.

The feedback will be used to prepare other jewelers for the challenges ahead, the organization said.

The online sessions are designed to teach jewelers to use AI tools like ChatGPT and Claude to grow their business.

The “United in Love” collection offers tangible mementos of hearts entwined with traditional and non-traditional commitment heirlooms.

Robert Goodman Jewelers will hold a “Black Jewelry Designers and Makers” event on April 27.

The announcements follow a tumultuous start to 2025 for WJA, which saw a wave of resignations following controversial statements about DEI.

Editor-in-Chief Michelle Graff answers questions about how the new taxes levied on countries like India and China will impact the industry.

Kenewendo, Botswana’s minster of minerals and energy, discusses closing the deal with De Beers and the work that was missed along the way.

The historic fancy vivid blue diamond set to headline Christie’s Geneva sale next month could sell for up to $50 million.

LVMH CFO Cécile Cabanis also discussed the effects of tariffs so far.

The “Mad Men” and “The Morning Show” star steals jewelry, art, and handbags from his wealthy neighbors in “Your Friends & Neighbors.”

The organization has reelected Kalpesh Jhaveri as president.

An investigation found that the former managing director of Movado’s Dubai branch overstated and prematurely recorded sales.

The collection pays tribute to the Japanese philosophy of Ma, studying balance, stillness, and the interplay between presence and absence.

Mari Lou’s Fine Jewelry in Orland Park, a suburb of Chicago, is closing its doors.

GIA’s labs in Dubai and Hong Kong are now accepting larger diamonds in light of the “logistical challenges” presented by the new tariffs.

These earrings by Van Cleef & Arpels, featuring the same design as a pair worn by Princess Grace, are up for auction at Woolley & Wallis.

Two experts share how artificial intelligence tools can help retailers run a more efficient business.

Kentaro Nishimura, who has been with the pearl company since 1997, has been promoted to president and CEO of Mikimoto America.

“America Telling Time: 150 Years of Bulova” explores the storied history of the American watchmaker.