Lifetime free cleaning and polishing service.

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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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Tours & workshops

Tours & Workshops

Experience the rich and royal heritage of Royal Coster Diamonds and the craft of diamond polishing while you also learn everything you need to know about diamonds.

Diamond Factory Tour

Explore the mystical world of diamonds in your own language. Watch our craftsmen and women cutting and polishing the most beautiful diamonds and see our goldsmiths making our jewelry collection.

Royal Experience

Since our establishment in 1840, royalties from all over the world came to Amsterdam to see and admire our craftsmanship. We’ve welcomed visitors like Empress Sisi, the Viceroy of China, King Rama V to Prince Napoleon. And now it’s your turn to visit.

Diamond masterclass

Do you want to learn the craft of diamond polishing from the best polishers in the world? And do you want to keep the diamond that you polished? Then this is the perfect experience for you!

Royal Engagement Experience

Are you getting engaged soon? And are you looking for a suitable ring with a unique diamond? Make it unforgettable with our special Royal Engagement Experience!

Luxury Shopping Experience

Due to our rich history and many years of experience, we are rightly seen as the authority in the field of diamonds. We offer the highest standard of certifications and guarantee fair and sustainable diamonds at all times.

Great For Events: the Champagne Diamond Surprise

Get the possibility to go home with a real diamond! Every guest receives a glass of champagne. In each glass, we have placed a real diamond or a cubic zircon. Who gets the real one?