That’s according to Queensmith’s 2026 Lab Grown Diamond Trends Report, which found a 22 per cent year-on-year rise in the carat weight of lab-created diamonds purchased from the UK jeweller. The average rose from 1.57 carats in 2025 to 1.92 carats in 2026.
Queensmith found that 46 per cent of its lab-created rings featured diamonds of at least two carats. Of these, 15 per cent weighed three carats or more, and four per cent at least four carats.
However, average spending increased marginally, rising from £4,172 ($AUD7,948) in 2025 to £4,234 ($AUD8,066) in 2026. The report noted that the lower cost of lab-created diamonds lets consumers prioritise size, quality, and personalisation without cutting their budgets.
Beyond weight and specifications, the report identified shifts in design preferences. Oval is currently the most popular diamond shape, while interest in elongated cushion, marquise, and emerald cuts is rising.
Demand for antique-inspired designs, particularly old mine-style cuts, is increasing – almost certainly as a result of the fanfare surrounding global pop icon Taylor Swift’s engagement ring. Laura Suttie, Queensmith’s gemmologist and design expert, attributed this trend to value, appearance, and availability.
"Requests to see old mine-cut diamonds have gone up, but most of these couples end up choosing a lab-grown cushion cut instead,” she said.
“A lab-grown cushion gives you beautiful sparkle at a lower price per carat, and you can still get that vintage feel through the setting, with a rubover, mixed metals or Georgian-inspired detailing."
Queensmith also reported rising demand for bespoke engagement rings. Examples include east-to-west settings, chunky bands, and rubover designs. CEO Brett Afshar pointed to buyers’ growing focus on personal preferences and ring choices.
“Buyers are increasingly thinking about what matters most to them personally, whether that is the size of the diamond, its quality or the design of the ring itself,” he explains.
“Lab-grown diamonds give customers more flexibility in how they approach that decision, and we’re seeing that reflected in the choices they make.”
A recent report in Australia highlighted the increasing popularity of lab-created diamonds amid a cost-of-living crunch.