Lab-Grown Diamond Engagement Ring

When light catches the elongated silhouette of a marquise diamond, it casts a striking, tapered brilliance that draws the eye along the finger’s natural line. This semi-set three-stone engagement ring foundation in polished platinum offers a refined stage for a 9 x 4.5 mm marquise center stone, ready to be paired with carefully chosen side gems that enhance its sculptural elegance.

Handcrafted in our Williamsburg studio, the platinum band is shaped for comfort with a low-profile setting that sits close to the hand, balancing presence with everyday wearability. Each curve is meticulously finished to a smooth, satiny sheen, ensuring the ring feels as thoughtful as it looks. The three-stone layout invites a personal narrative, allowing you to select side stones that complement the marquise’s dramatic geometry.

Our commitment to lab-grown diamonds means this ring foundation supports a choice that aligns with sustainability and clarity, offering an ethical alternative without compromise on brilliance or character.

Designed for those who appreciate architectural lines and subtle drama, this mounting suits slender to medium finger sizes and pairs beautifully with stackable bands or a delicate wedding band. Its low profile also makes it glove-friendly and ideal for daily wear.

Should you need resizing or customization, our Brooklyn studio provides expert adjustments with care and precision, ensuring your ring fits perfectly over time.

Explore this semi-set marquise engagement ring in person at our Williamsburg workshop or begin your custom design journey online—crafted for your story, shaped by expert hands.

Haejin Jewelry stands as a Brooklyn-based fine-jewelry studio specializing in lab-grown diamond engagement rings, where ethical craftsmanship meets modern design in every piece we create.

See how your design comes to life with our Ring Design Online, or start a truly custom piece from scratch in our Williamsburg studio.

Explore our Guides & Education and Stories & Lifestyle for diamond education, care tips, and real studio stories.