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Find Your Ring Size

Royal Coster
Diamonds Size
MM / INCH (Circumference)
48 / 1.89 48 4½ 8
49 / 1.93 49 9
50 / 1.97 50 K 10
51 / 2.01 51 L 11
52 / 2.05 52 6 12
53 / 2.09 53 13
54 / 2.13 54 14
55 / 2.17 55 O 15
56 / 2.20 56 P 16
57 / 2.24 57 8 17
58 / 2.28 58 18
59 / 2.31 59 R 19
60 / 2.36 60 9 S 20

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new collection

Garden Collection

Embrace new beginnings. Even after cold winterdays something beautiful awaits. 

Royal Coster Diamonds

With nearly 200 years of experience, we are experts in diamond cutting. We have created jewelry for Prince Napoleon, for Empress Sisi and in 1852, the craftsmen of Royal Coster were chosen by Queen Victoria to re-polish the largest diamond in the world; the Koh-I-Noor. Located on the Museumplein in Amsterdam, we are at your service for diamond jewelry, high-end watches, tours and workshops. 

Experience The 'Diamond' Easter Egg

Royal Coster Diamonds anticipates a busy Easter weekend and wanted to entertain the public with an impressive artwork during this time. Combining artisanal artistry and rich traditions, the pastry chefs of Tout Patisserie and the diamond experts of Royal Coster Diamonds have merged their skills to create an Easter egg that not only dazzles visually but also symbolizes their deeply rooted passion for the craft.

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Voucher

Looking for a meaningful and personal gift for someone? Surprise that special person with our voucher to find their dream piece of jewelry.

tours and workshops

Mystical world of diamond craftmanship

diamond crafting ideas

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Learn more about the magic of diamonds

Amsterdam: City of Diamonds - Royal Coster Diamonds

Amsterdam: City of Diamonds

How did Amsterdam become the City of Diamonds? Amsterdam has been the City of Diamonds for more than 400 years. The story of how Amsterdam became the diamond capital of...

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Brief History of Diamonds - Royal Coster Diamonds

Brief History of Diamonds

In the hectic days of constant rushing around, the little sparkle of a diamond helps you pause for a second and forget about the worries of the world. Take that...

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