Online diamond jewellery retailer James Allen now offers lab-grown diamond  jewellery alongside natural diamond jewellery making U.S.'s largest jewellery retailer Signet enter the lab-grown diamond market. James Allen was acquired by Signet in 2017. 

Lab-grown diamonds will be offered on engagement rings and the retailer promises, “up to 30% more size for the same cost.” 

A lab-created 4.49ct ct F-VS1 emerald cut diamond costs $48, 350 while a 5.22 ct H-SI1 emerald cut natural  diamond costs $72,600. The lowest carat size on offer in the lab-grown diamond space by the online retailer is 0.70ct oval cut diamond in E-SI1 clarity for $1320.