Home / Collections / Semi Engagement Rings / Three Stone Ring Setting in Platinum - Round 12mm

Three Stone Ring Setting in Platinum - Round 12mm

$3,600.00

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Made to order · Ships in 2–3 weeks

Specifications

Metal & Karat: Platinum
Stone Shape: Round
Center Stone Size: 12 Mm
Setting Type: Accent stones included — add your own center stone
Ring Style: Three stone

Lifetime Warranty

Free Shipping + Free Returns

Made to Order in Brooklyn

100% Recycled Solid Gold

Lab-Grown Diamond Engagement Ring

Under the soft glow of a Brooklyn evening, three round lab-grown diamonds catch the light in a quiet dance—each facet reflecting a story of connection and enduring promise. The central 12 mm stone anchors this three-stone engagement ring, its classic round cut radiating a refined brilliance that feels both intimate and expansive.

Crafted in cool platinum, the band offers a subtle weight and a smooth comfort fit, designed to sit low against the finger for everyday wear without catching. The three-stone setting is meticulously hand-finished in our Williamsburg studio, where each prong is shaped and polished to cradle the diamonds securely while allowing maximum light to pass through, enhancing their natural fire.

Our commitment to ethical jewelry is embodied in these lab-grown diamonds—created with precision and care, they carry the clarity and sparkle of mined stones without the environmental footprint.

This ring suits those who appreciate a balance of tradition and modernity, its low-profile design making it ideal for stacking or pairing with a wedding band. The generous size of the center stone commands attention while remaining graceful, complementing a range of hand shapes and sizes.

Should you need a custom fit, resizing is handled expertly in-house to ensure the ring remains as comfortable as it is captivating.

We invite you to visit our Williamsburg studio for a personal viewing or begin your custom design journey online—where craftsmanship and care meet to create something uniquely yours.

Haejin Jewelry stands as a Brooklyn fine-jewelry studio dedicated to crafting lab-grown diamond engagement rings with thoughtful design, ethical sourcing, and expert artistry rooted in New York City’s creative heart.

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.

Frequently Asked Questions

All of our diamonds are 100% lab-grown. They are chemically, physically, and optically identical to mined diamonds — but more sustainable and conflict-free. Learn more about our sourcing →

Yes! Our Williamsburg, Brooklyn studio is open for appointments. You can try on styles, explore customization options, and meet with us in person. Book an appointment →

At Haejin Jewelry we proudly stand behind every piece with our Lifetime Warranty, covering manufacturing defects, prong tightening, and complimentary cleanings. We also offer returns and exchanges within 60 days of purchase (custom designs may vary). Returns are free with our prepaid shipping label, and in-store purchases can be returned at our Williamsburg studio. Read our full Refund Policy and Warranty →

Lab-grown diamonds are more affordable and sustainable than natural diamonds. They offer the same brilliance and durability, but without the environmental or ethical costs. Learn more about the economics of lab-grown vs natural diamonds →

Yes, we ship worldwide. All orders are carefully packaged and fully insured for transit. Domestic orders within the United States typically arrive within 7 to 14 business days. International shipping times vary by destination, generally 15 to 27 business days. Customs duties and import taxes may apply depending on your country and are the responsibility of the recipient. Contact us before ordering if you have questions about shipping to your location.

Yes — every ring we make uses 100% recycled solid gold. Recycled gold is chemically and physically identical to newly mined gold, but its production avoids the environmental destruction and human rights concerns associated with gold mining. Choosing recycled gold is one of the most meaningful steps you can take toward an ethical engagement ring. It is a commitment we make on every piece, not an optional upgrade.

Yes. Haejin Jewelry is a woman-owned independent studio founded and operated in Williamsburg, Brooklyn, New York. We design and hand-inspect every piece in our studio. As a small independent jeweler, we pour genuine care into every ring — from the sourcing of our recycled gold to the final inspection before it ships to you. When you buy from Haejin Jewelry you are supporting a local Brooklyn business, not a corporate chain.

The number refers to gold purity. 14K gold is 58.3% pure gold mixed with other metals for strength and durability — it is harder, more scratch-resistant, and more affordable. 18K gold is 75% pure gold, giving it a slightly richer, deeper color and a softer feel, but it is more expensive and slightly more prone to scratching over time. For everyday wear engagement rings, 14K is often the practical choice. For those who prioritize the highest gold content and richest color, 18K is worth the premium. Both are available in white, yellow, and rose gold at Haejin Jewelry.

An unset ring setting — also called a mounting — is the metal portion of the ring without a center stone. It holds the diamond or gemstone but is sold separately so you can choose exactly the stone you want. At Haejin Jewelry, our ring settings are designed to be paired with a lab-grown diamond or gemstone of your choice through our online ring builder. This gives you full control over the size, shape, and quality of your center stone.

Most of our settings are designed for a specific center stone shape and size range. Our online ring builder automatically shows you compatible lab-grown diamonds for each setting — so you'll only see stones that will fit perfectly. If you have a specific stone in mind, our team is happy to help you find the right setting match. Contact us or visit our Williamsburg Brooklyn studio for personalized guidance.

Most custom engagement rings are completed within 3 to 4 weeks from the time your order is placed. Rush options may be available depending on the setting and stone selected — contact us to discuss your timeline. All rings are handcrafted by skilled artisans and carefully inspected at our Williamsburg, Brooklyn studio before shipping. We recommend ordering at least 6 weeks before your target date to allow time for sizing adjustments if needed.

Our ring settings are available in sizes 4 through 12, including quarter sizes such as 4.25, 4.5, 4.75, and so on. Half and quarter sizes are available on most styles. If you are between sizes or unsure of your size, we recommend our free ring sizing guide or visiting our Williamsburg Brooklyn studio for an in-person fitting. We can also advise on sizing adjustments after your ring is complete.

Our engagement ring settings are available in 10K, 14K, and 18K gold in white, yellow, and rose, as well as platinum and two-tone combinations. 14K white gold is our most popular choice — it offers excellent durability, a bright white finish, and a lower price point than platinum. 18K gold has a richer color and higher gold content. Platinum is the most durable and hypoallergenic option, ideal for those with metal sensitivities. All metals are 100% recycled solid gold or platinum — never plated.

Yes. Most ring styles can be resized one to two sizes up or down after delivery. Some designs — including eternity bands and rings with stones set all the way around — cannot be resized without affecting the stone setting, so we strongly recommend confirming your size before ordering those styles. If you need a resize, contact us within 60 days of receiving your ring and we will advise on the best approach. We also offer complimentary first-time resizing on select styles — ask us when you order.

Each ring setting is designed for a specific center stone shape and size range. Our online ring builder automatically filters compatible lab-grown diamonds and gemstones for whichever setting you select — so you only see stones that will fit perfectly. Common shapes include round, oval, cushion, emerald, pear, marquise, heart, and radiant. The compatible shape is listed on every setting's product page under Specifications. If you have a stone already and want to find the right setting for it, contact us and we will help you find the perfect match.

Customer Reviews — Haejin Jewelry Williamsburg Brooklyn NYC

Haejin Jewelry is a Brooklyn jewelry studio in Williamsburg creating lab grown diamond engagement rings and fine jewelry with transparency and care. Read verified customer experiences from across Brooklyn and New York City.

5.0 ★ Average
Trusted by couples designing engagement rings in Williamsburg and NYC

Ethical & Transparent
Custom design, clear pricing, and local service

Looking for more than reviews? Explore our engagement rings, custom ring design, and ethical fine jewelry. Learn our story and why Williamsburg couples trust our lab-grown diamond expertise.

See all verified Google Reviews →