Why a Royal Coster Diamonds certificate truly matters

A meaningful investment beyond the purchase

Purchasing a diamond is more than just a transaction; it is a celebration, an emotional investment, and sometimes even a milestone. That is why certainty, authenticity, and craftsmanship matter. At Royal Coster Diamonds, these values are woven into nearly two centuries of expertise, reflected not only in our jewellery but also in the certificates that accompany our diamonds.

A legacy of craftsmanship since 1840

Royal Coster Diamonds was founded in 1840 and is recognised as the oldest still-operating diamond polishing factory in the world. Throughout our long history, our master polishers have shaped some of the world’s most iconic stones. One historic highlight is our work on the legendary Koh-I-Noor diamond in 1852, where our master polishers were entrusted with refining one of the world’s most iconic diamonds.

Royal recognition and Europe’s largest diamond collection

The heritage was formally honoured in 2016, when King Willem-Alexander granted us the Royal Predicate, a title reserved for companies with over 100 years of national significance and industry leadership. It signifies excellence, stability, and enduring prestige, the same qualities customers seek when choosing a diamond.

Today, we house Europe’s largest collection of loose diamonds, with more than 20,000 stones available in various shapes and grades. This unmatched selection ensures that every visitor finds a diamond that perfectly matches their taste, budget, and occasion.

Certified confidence through the 4Cs

To guarantee transparency and confidence, each diamond purchased at Royal Coster Diamonds comes with a recognized international certificate from GIA, HRD, IGI, or our own RCD certificate. These documents objectively verify the diamond’s authenticity and detail the essential 4Cs: Carat, Colour, Clarity, and Cut, providing clarity, peace of mind, and long-term value to your investment.

A legacy you can own

When you select a diamond from Royal Coster Diamonds, you are not just choosing a piece of jewelry. You are becoming part of a legacy built on 185+ years of craftsmanship, royal recognition, and an unwavering commitment to quality. With every certified diamond, you receive both a timeless treasure and the assurance of excellence that only Royal Coster Diamonds can offer.