Lab-grown diamonds have shifted 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. At C. Blackburn Jewelers, Blackburn increasingly works with couples who arrive at consultations already considering a lab-grown diamond, and often specifically requesting one.
"Just a few years ago, people would come in asking whether they should even consider a lab-grown diamond," Blackburn said. "Now, many couples already know it is an option and want to see what their budget can achieve with one."
The shift in La Jolla mirrors a broader national trend. 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. That majority status matters for jewelers, designers and the couples they serve, because it changes how buyers approach the single most expensive component of a ring.
For many couples, Blackburn says, the appeal begins with value. Because lab-grown diamonds typically cost substantially less than comparable natural diamonds, buyers may be able to choose a larger center stone, improve color or clarity, or devote more of their budget to the design and craftsmanship of the ring itself.
"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."
Lab-grown diamonds have essentially the same chemical composition and crystal structure as naturally formed diamonds and share the same hardness and optical properties. Their principal difference is origin. Motivations vary: some couples are driven mainly by price, while others prefer a diamond that does not require traditional mining or want greater transparency about how their stone was produced.
The economics also influence expectations around size. The same 2026 study from The Knot found that lab-grown diamond center stones averaged 2.0 carats, compared with 1.6 carats for natural stones. Blackburn says that difference can be especially significant in custom engagement ring 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," Blackburn said. "When clients have more flexibility with the center stone, it gives us more possibilities for the ring surrounding it."
Blackburn continues to design engagement rings featuring natural diamonds for clients who value their 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," Blackburn said. "What matters is understanding what you are buying and choosing the stone that makes sense for you."
For couples who choose lab-grown, Blackburn says the decision increasingly comes without the hesitation that surrounded the category when the stones first entered the consumer market.
"What has changed most is the conversation," Blackburn 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."
"Whether the diamond came from the Earth or a laboratory, it is only one part of the engagement ring," Blackburn said. "The meaning comes from the people, their story, and the design we create around it." Couples and trade professionals seeking more information can visit CarlBlackburn.com.
