ROCK DOC: A native of South Africa, David Blank opened Diamond Doctor in 2002 and since has become the “Offical Jeweler of the Dallas Cowboys.”

How David Blank Finds Diamonds in the Rough

Marketing to both “the classes and the masses,” he's made his wholesale company an industry leader in North Texas.

South Africa native David Blank has grown his wholesale diamond business into one of the largest operations of its kind in North Texas, serving some of the region’s most prominent people. But the president of Diamond Doctor sees his business as one that’s in its infancy. “Despite our position, I see this as a fledgling company,” he says. “We could still double or triple our sales from here.”

Blank does business as a diamond wholesaler, selling diamonds at wholesale prices to both retail resellers and to individual customers, from a single, ultra-upscale location in the heart of Dallas on Preston Road and Sherry Lane. His access to numerous supply chains enables him to buy diamonds—including entire inventories—from cutters and dealers. He then sorts these stones, distributing the lower-quality ones for wholesale sale and the “crazy expensive ones” to auctions or diamond houses, while keeping the “most sellable ones” to sell to individuals. This model, he says, allows him to market to “the classes and the masses.” 

Blank purchased the two-story building on Preston during the depths of the Great Recession, which he calls one of the most opportunistic times in the company’s history. Besides snapping up the then-vacant office building for a song, he spent much of 2008 and 2009 buying diamonds at rock-bottom prices. 

“During the recession, a lot of diamond dealers and individuals were stretched for cash,” he says. “I bought every single diamond I could get my hands on, some for 50 cents on the dollar. Within seven or eight months, the market had recovered.”

Since coming to North Texas from South Africa in 1996, Blank, who has a degree in accounting, has been all about uncovering the opportunity in any situation. He traveled to the United States to attend his sister’s wedding, not long after a gunpoint robbery at his diamond business in South Africa, and fell in love with Dallas. 

Blank partly credits the success of his 40-employee company to his decision early on to pinpoint men in search of engagement and special-occasion rings.

He went to work for a local wholesale diamond business owned by a friend’s father, and was handed a telephone book to cold-call jewelry stores. Blank turned what could have been a dead-end job into a booming enterprise within the business. “I don’t know if it was my accent or that I was legitimately from South Africa and had diamond ties or what, but I was good—really good,” he says. “I had the ability to really connect with people.”

Blank capitalized on those connections by breaking off on his own, opening the doors to Diamond Doctor as a diamond wholesaler, primarily to resellers, in a Galleria office tower in 2002. He began making a name for himself as somewhat of an industry wizard after successfully ending a long search for a rare type of diamond for a USAA client who was trying to replace a unique lost ring. USAA, the San Antonio-based insurance and financial services firm for military members and their families, remains one of the company’s biggest clients.

After Blank opened Diamond Doctor’s high-profile location on Preston in 2011, what he calls the retail side of the business (selling diamonds at wholesale prices to individuals) began eclipsing the wholesale side to resellers, and now accounts for more than half the company’s $40 million in annual revenue. 

“I made the decision to go back to being a big fish in a small sea,” says Blank, who does business locally as well as internationally. “I liked dealing with individuals. They appreciate what you are doing for them more than stores—they see how it is special.”

Blank partly credits the success of his 40-employee company to his decision early on to pinpoint men in search of engagement and special-occasion rings as his target market. Toward that end, he formed marketing partnerships with the Dallas Cowboys, Sportsradio 1310-The Ticket, the Cattle Baron’s Ball, and other high-profile organizations.

Clients now include several Cowboys players (Diamond Doctor is the “Official Jeweler of the Dallas Cowboys”) as well as prominent business and society couples including Lee Ann and Alan White, Aileen and Jack Pratt, Lana and Barry Andrews, and Tricia and Gil Besing. Blank’s largest sale ever was a 25-carat diamond for a 25th wedding anniversary that cost $3 million.

Longtime client Jerry Meyer, an investor in Eatzi’s, Just Brakes, and other companies, says he was impressed by Blank’s ability to sell jewelry at wholesale prices by cutting out several links in the supply chain—a business strategy that Meyer appreciates as an entrepreneur.

Blank “is such a straight-shooter, which is a really admirable quality in this business,” Meyer says. “You don’t cut as big as a swath in this town as he has cut without doing something right. He has positioned himself at the top of the food chain.”

Approaching the jewelry business from such a position of strength has enabled Blank to continuously carve out new revenue streams. He says he typically carries an at-cost inventory of $20 million to $50 million—numbers that will swell to $100 million for a special diamond event in December.

Although he decided early on to concentrate solely on diamonds—forgoing the temptation also to dabble in watches and other accessories—Blank has now shifted his attention to diamond cutting, entering that niche after snapping up a fifth-generation Dallas diamond-cutting company. 

Early next year, Diamond Doctor will consolidate the cutting business into a 12,000-square-foot facility in Farmers Branch, making Blank’s supply chain even more vertical.

“We are successful, but I still come to work every day with butterflies in my stomach, wondering how the business is going to go,” says Blank, who says he’s aiming for $100 million in annual revenue. “I never stop thinking about how we can continue to diversify and grow.”  


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