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The oldest diamond cutting factory in the world was founded in 1840 by Moses Elias Coster.


Martin Coster moves to Paris where he sets up a polishing factory. Coster acquires a near-monopoly on diamond cutting in the world’s jewelry capital.

Medal Of Honor

The entire Amsterdam diamond industry wins a Medal of Honor at the World Exhibition in Paris. In particular Mr. Voorzanger for repolishing the Koh-I-Noor.

The Star Of The South

A rare diamond was discovered in Brazil. Coster Diamonds buys it for $35,000 and repolishes the diamond into a 128.48-carat stone.

World Exhibition Paris

Martin Coster builds a replica of the polishing factory at the World Exhibition in Paris. It becomes one of the highlights. In 1868, King Willem III appoints Martin Coster Consul General of the Netherlands.

Portrait Of King Willem III

One of the most talked about exhibitions is Coster’s large diamond with King Willem II’s portrait engraved in it.

Passing Of Martin Coster

Martin Coster passes away in Paris. His impressive tombstone is located in the heart of Montmartre Cemetery in Paris.

Olympic Games In Amsterdam

In addition to the Olympics, the tourist book also mentions the diamond polishing factory Coster as a place worth to visit.

City Of Diamonds

Under the name ‘Amsterdam City of Diamonds’, Coster Diamonds and a few other diamond houses organize an exposition. All participants receive a gold medal.

Repolishing The Koh-I-Noor

Two of Coster’s best polishers, Mr. J.A. Fedder and Mr. L.B. Voorzanger, repolish the Koh-I-Noor for Queen Victoria in London.

Diamond Watch

The Dutch people give a bracelet watch to Her Majesty Queen Juliana for her 50th birthday. Diamond polisher Ben Meier polished the diamonds for the watch.

New Owner

Together with business partners Joop Schoos and Max Meents, Ben Meier becomes the owner of Coster Diamonds and creates a new future for the company.

New Location

Coster Diamonds finds a new accommodation at the Museum Square.

World Record

Diamond polisher Pauline Willemse polishes 57 facets on a stone. Weighing 0.0000743 carats, it is the smallest diamond in the world.

The Royal 201

Mr. Bobby Low and Donny Griffioen of Coster Diamonds introduce a new patented diamond cut with 201 facets. This new cut is called the Royal 201 and to this day, it is the most sparkling diamond shape in the world.

Intangible Cultrural Heritage

The craft of diamond worker is proclaimed official Intangible Cultural Heritage of the Netherlands. Coster Diamonds is one of the few companies in the Netherlands where the profession is still in practice.


King Willem-Alexander of the Netherlands grants Coster Diamonds the Honorary Title ‘Royal’ turning Coster Diamonds into Royal Coster.

Royal Coster’s Crest

Royal Coster develops a crest that belongs to our Royal Title. The crest contains all subjects that represent the core values of our company. At the same time, it is a tribute to Martin Coster.

Honor Of The Golden Age

Diamond Worker Craft is honored with a unique diamond medal in honor of the ‘Golden Age’ that year. The diamond craft receives a place on the Representative List on Intangible Heritage of Humanity from UNESCO.

Introduction Royal Signature C Collection

This collection features a unique open setting designed exclusively for the Royal 201 diamond cut.

New Boutique

Royal Coster Diamonds opens her “Luxury House” located at Paulus Potterstraat no. 6.

We Go Beyond Expectations

The world’s oldest and most trusted diamond factory has a rich and compelling history. Royal Coster Diamonds is around for a long time, dating back all the way to at least 1840.

How Do We Do This?
Largest stock of loose diamonds in Europe
With 20.000 loose diamonds in stock, we have the biggest collection in Europe. If you’re looking for that one special diamond, we can probably provide you with it!

Our diamond jewelry is handmade inhouse
Our diamond polishers and goldsmiths polish and create the jewelry themselves. In their workshop they create the most fascinating and unique masterpieces.

Four monumental villas in the heart of Amsterdam
Discover something in every building! See how our craftsmen work on diamond jewelry and enter the world of diamonds in one of our luxurious showrooms.


What Does This Mean?

For every taste
Whatever style you prefer, you are in the right hands with us! From solitaire rings, to tennis bracelets and big statement pieces. We got it all. And if you still can’t find that perfect jewel? Our craftsmen can easily create a one-of-a-kind piece for you.

The most trusted jeweler
Since 1840 many customers have trusted the craftsmen of Royal Coster for their jewelry. Among which royals from all over the world, such as Empress Sisi, King Rama V of Thailand and the Viceroy of China. We work with the highest quality diamonds and our diamond polishers are known for their expertise.

Countless satisfied customers
At Royal Coster we don’t only sell diamonds and diamond jewelry, we create stories of happiness and love. We are proud and grateful to be a part of your love journey.

Royal Coster’s Royal visitors
We always shared a warm relationship with Royals. Not only the Royal House from the Netherlands, but Royal Houses from all over the world. Since our foundation in 1840, a lot of royals traveled to Amsterdam to trust us with their jewelry. They knew that Coster used an innovative way of cutting and polishing diamonds. To this day, our fantastic craftsmanship attracts royals and celebrities from all over the globe.


A special assignment
Normally, people come to us. But for Queen Victoria of England, we gladly made an exception. In 1852, two of our best diamond polishers went to London. They had the task to repolish the world famous Koh-i-Noor diamond. This is one of the most valuable diamonds around and part of the English Crown Jewels. Even today, it is one of the finest examples of craftsmanship in diamond history.

In the second half of the 19th century, the British Royal House wasn’t the only royal name trusting us with their jewelry. Among the royals we welcomed were Napoleon Bonaparte, Prince Victor Emanuel, and Empress Sisi. Our list of famous visitors is long and unique. Especially when you consider that traveling at the time was an expensive luxury. It was done seldom, which makes this royal list even more impressive.