NeighbourhoodMuseum Quarter
Historic Craftsmanship
Royal Coster Diamonds
Step inside the world's oldest diamond polishing factory to witness the precision and artistry behind the world's most coveted gemstones.
Best forCraftsmanship & Luxury
Plan for45–60 minutes
Worth knowingFree tours in 35 languages
A Legacy of Brilliance
Amsterdam’s Diamond Heritage
Royal Coster Diamonds stands as a testament to Amsterdam's long-standing reputation as the 'City of Diamonds.' Established in 1840, it holds the distinction of being the oldest diamond polishing factory in the world still operating in its original craft. Located prominently on Museum Square, it serves as both a working factory and an educational destination for those curious about the journey from raw stone to brilliant jewel.
The facility is renowned for its accessibility, offering guided tours that explain the '4 Cs'—carat, color, clarity, and cut—while providing a live look at master polishers at work. With a collection of over 20,000 loose diamonds, it is one of the largest hubs for certified natural diamonds in Europe, maintaining strict standards through certifications from GIA, IGI, and HRD.
Since 1840
From Coster to Royal
The factory was founded by Moses Elias Coster in 1840. Over the decades, it became a focal point for international royalty and high society. One of its most significant historical milestones occurred in the mid-19th century when Prince Albert of Great Britain commissioned Coster to re-polish the famous Koh-i-Noor diamond, which is now part of the British Crown Jewels.
In 2016, the institution reached a new pinnacle when King Willem-Alexander of the Netherlands granted it the 'Royal' title. This honorary designation is reserved for organizations that have existed for at least a century and are recognized as undisputed experts in their field. Today, the factory continues to blend these traditional techniques with modern precision.
What to See
The Diamond Experience
Live Craft
Polishing Benches
Observe master polishers as they use specialized tools to shape raw stones. You can see the intense focus required to create the perfect facets that give diamonds their fire.
Global Access
Multilingual Tours
The factory offers free guided tours in 35 different languages, ensuring that international visitors can fully understand the technical nuances of diamond grading.
The Collection
Loose Diamonds
Explore one of Europe's most extensive inventories, featuring over 20,000 natural diamonds. Experts are on hand to explain the certification process and stone origins.
Visitor Flow
Your Visit Experience
Morning
Quiet Exploration
Arrive shortly after opening at 9:00 to enjoy a more personal interaction with the guides before the midday museum crowds arrive at Museum Square.
Afternoon
Workshop Sessions
For a deeper dive, book a specialized Diamond Experience or workshop where you can learn the basics of diamond valuation in a structured setting.
Closing
Final Viewings
The factory typically closes at 17:00. Use the final hour to browse the fine jewelry showroom after completing your factory tour.
Visuals
Inside the Factory
The interior of Royal Coster Diamonds balances the industrial feel of a working factory with the elegance of a high-end showroom. Visitors can see the contrast between the heavy machinery used for cutting and the delicate, sparkling results displayed in the galleries.
Need to Know
Visitor Information
Royal Coster Diamonds is located at Paulus Potterstraat 2, directly between the Rijksmuseum and the Van Gogh Museum. This makes it an easy addition to a day spent exploring the Museum Quarter.
Official websiteHours
Daily Access
The factory is open daily from 9:00 to 17:00, including weekends.
Booking
Tour Reservations
While walk-ins are often welcome for the free tour, booking in advance is recommended for specific language requirements or specialized workshops.
Bookable experiences
Experiences around Royal Coster Diamonds.
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Getting There
Transport Links
The factory is highly accessible via Amsterdam's public transport network. Tram lines 2, 5, and 12 stop at the 'Museumplein' station, which is just a short walk from the entrance. If you are coming from the city center, the walk through the Spiegelkwartier offers a scenic route filled with antique shops.
Questions
Common Inquiries
Is the guided tour really free?⌄
Yes, Royal Coster Diamonds offers a basic guided factory tour free of charge to educate visitors on the diamond polishing process.
Can I buy diamonds directly from the factory?⌄
Yes, they have a vast showroom with over 20,000 loose diamonds and a wide selection of fine jewelry available for purchase.
Are the diamonds ethically sourced?⌄
Royal Coster Diamonds works exclusively with natural diamonds that are certified by independent institutes like GIA and IGI to ensure authenticity and quality.