Lab-grown diamonds have transitioned from an alternative option to a mainstream choice for custom engagement rings, and San Diego jewelry designer Carl Blackburn says the change is visible in his La Jolla studio, where couples increasingly arrive already considering or specifically requesting a lab-grown stone.
The shift carries significance beyond a single studio. According to The Knot's 2026 Real Weddings Study, lab-grown diamonds accounted for 61 percent of engagement ring center stones purchased by couples in 2025, a majority share that signals how quickly consumer preferences have moved in a category long dominated by mined stones.
Blackburn, who leads C. Blackburn Jewelers, said the nature of client conversations has changed markedly. "Just a few years ago, people would come in asking whether they should even consider a lab-grown diamond," he said. "Now, many couples already know it is an option and want to see what their budget can achieve with one."
For buyers, the appeal often begins with value. Because lab-grown diamonds typically cost substantially less than comparable natural diamonds, couples may be able to select a larger center stone, improve color or clarity, or direct more of their budget toward design and craftsmanship. "For some couples, it means choosing the two- or three-carat diamond they really wanted instead of compromising on size," Blackburn said. "For others, it means putting more of their budget into creating a completely custom ring."
The economics also shape expectations around size. The same 2026 study found that lab-grown diamond center stones averaged 2.0 carats, compared with 1.6 carats for natural stones. Blackburn said that difference matters in custom design, where the proportions of the center diamond influence the entire look of the ring. "A larger diamond can completely change the architecture of a design," he said. "When clients have more flexibility with the center stone, it gives us more possibilities for the ring surrounding it."
Chemically and structurally, lab-grown diamonds are essentially the same as naturally formed diamonds, sharing the same hardness and optical properties; their principal difference is origin. Motivations among couples vary, from price to a preference for stones that do not require traditional mining or that offer greater transparency about production.
Blackburn continues to design rings with natural diamonds for clients who value rarity, geological history, family significance or traditional appeal. "There are good reasons someone might choose a natural diamond, and there are good reasons someone might choose lab-grown," he said. "What matters is understanding what you are buying and choosing the stone that makes sense for you."
For couples choosing lab-grown, Blackburn said the decision increasingly comes without the hesitation that once surrounded the category. "What has changed most is the conversation," he said. "People aren't necessarily asking, 'Is it okay to buy lab-grown?' anymore. They're asking what size, shape and design they can create with it." More information about the studio's work is available at CarlBlackburn.com.
