Marquise Lab-Grown Diamond Three Stone Engagement Rings Under £3,500

Lab-grown diamonds are chemically, physically, and optically identical to mined diamonds. They have the same crystal structure, hardness (10 on the Mohs scale), refractive index, and thermal conductivity. The only difference is their origin — grown in a controlled laboratory environment in 6–10 weeks rather than formed over billions of years. Lab-grown diamonds are typically 60–80% less expensive than equivalent natural diamonds, allowing you to choose a larger, higher-quality stone within your budget.

The marquise cut features a distinctive elongated shape with pointed ends, offering the largest face-up area of any diamond shape for its carat weight. Its boat-like silhouette creates a dramatic, regal presence on the finger and makes the stone appear significantly larger than other shapes of the same weight.