After a summer of hype and speculation, Lightbox, De Beers’ lab-grown diamond line, officially debuted in September—and so far, it hasn’t shaken the industry as much as some anticipated.

Initial sales were healthy, says chief marketing officer Sally Morrison, though she admits that many of the first orders may have come from ­curious industry competitors.

Skeptics, particularly rival lab-grown diamond sellers, pointed out that the most talked about Lightbox offering—a pendant with a 1 ct. white center stone—has been sold out since last fall’s launch, causing them to doubt De Beers’ claim that it was selling lab-grown diamonds for $800 a carat. (The other 1 ct. items are all total weight.) General manager Steve Coe says that the site is continually being refreshed, and the trade should expect more 1 ct. items in the future.

As for the jewelry itself, one buyer found the pieces “good commercial merchandise like you see from the TV shopping companies. Everything about them screams ‘pretty good,’ while nothing about them says ‘fantastic.’ Something tells me this is deliberate. They don’t want fantastic.”

The new brand will produce its blue, pink, and white diamonds at a 60,000-square-foot factory in Gresham, Ore.—which, because of its energy needs, is located next to a power station. The complex’s ­diamond-growing machines can spit out the stones with relative consistency, says Adam O’Grady, head of special projects for Element Six, the synthetic-producing subsidiary of De Beers. “There is always some variability, but the variability is a single-digit percent,” he says.

Unusual for the industry, the brand is being marketed on podcasts, including Oprah Winfrey’s—which shows that it is not as millennial-focused as some assumed.

In the last week of November, the brand debuted its first pop-up store at the Oculus at Westfield World Trade Center in New York City. The 20-foot by 20-foot cube didn’t sell product—only displayed it—but ­provided an opportunity to build brand awareness and find out more about how consumers perceive lab-grown stones, says Morrison.

While competitors have been uneasy about De Beers encroaching on their turf, some believe that it has helped acceptance of their ­product. Richline Group says De Beers’ announcement gave its man-made line, Grown With Love, a boost at JCK Las Vegas. It is now carried by Macy’s and J.C. Penney.

Top: 0.75 ct. t.w. Blue Moon pendant, $700, 0.5 ct. t.w.  halo pendant in pink, $500, 0.5 ct. solitaire pendant in pink, $500; lightboxjewelry.com