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Lifetime free cleaning and polishing.

Free resizing service.

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Why not explore our new Luna Collection?

Find Your Ring Size

Royal Coster
Diamonds Size
Internal Diameter / Circumference (mm)​
14,01
14,33
14,65
14,97
15,21
15,61
15,92
16,24
16,56
16,88
17,20
17,52
17,83
18,15
18,47
18,79
19,11

How To Measure

The Hands-on Method​ Measure an Existing Ring
  • 1. Grab a tape measure, length of string or strip of paper.
  • 2. 2. Wrap one of these objects around your finger. Mark the place where the two end of the measuring object come together.
  • 3. When using string or paper grab a ruler. Lay it on a flat surface and measure to where the marked point is.
  • 4. Use the chart presented above to acquire the correct ring size.

The engagement workshop

A diamond is a physical manifestation of love and affection. Our master craftsmen and -women create the most wonderful diamond jewelry and precious diamonds for Royals around the world since 1840. And today you and your loved one can become a part of that legacy.

Our engagement workshop is for couples who are preparing for an engagement or anniversary and want to learn more about diamonds before they purchase. Buying an engagement ring is special on itself but when combined with learning how to truly appreciate diamonds, makes it an unforgettable experience.
If you are thinking about proposing in a unique way, the Engagement Workshop is a great way to do this. It’s romantic, it’s original and it’s unexpected. It’s perfect!

What do you get?

- Guided personal tour

- Explanation of the 4 C's of diamond polishing

- See famous diamond artefacts

- Create your diamond engagement ring

- Experience to polish a diamond

- Free glass of champagne

Experience Luxury Shopping in the heart of amsterdam

free diamond tour & workshops

visit royal coster

Book an experience and learn about our heritage or visit us to see more diamonds & jewelry