At the heart of it since 1840.

At the heart of it. Since 1840.

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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.

Blogs

Read more about diamonds, knowledge and the rich history of Royal Coster

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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The 1st C: The Carat - Royal Coster Diamonds

The 1st C: The Carat

For many people, buying a diamond is not an everyday business. It seems quite difficult already. But if you dive deeper in the world of diamonds, it appears even harder...

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The 2nd C: The Color - Royal Coster Diamonds

The 2nd C: The Color

The color of a diamond –or rather the lack of it – tells us something about the value and quality of the diamond. A diamond that consists of carbon only...

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The 3rd C: Diamond Clarity - Royal Coster Diamonds

The 3rd C: Diamond Clarity

The 3rd of the four c’s we discuss in this series is the clarity of a diamond. A natural diamond is rarely without imperfections. It is a hallmark of Mother...

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The 4th C: Diamond Cut - Royal Coster Diamonds

The 4th C: Diamond Cut

The fourth of the four C’s in this sequence is the Cut, or shape of a diamond. The shape is important to determine the quality of the polished diamond. The...

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What is a Diamond Certificate? - Royal Coster Diamonds

What is a Diamond Certificate?

Stress, sweating, nervousness… these are all common aspects of future fiancées-to-be when planning to buy the perfect diamond ring. “What if my partner does not like it? What if it...

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What are Synthetic or Lab Grown Diamonds? - Royal Coster Diamonds

What are Synthetic or Lab Grown Diamonds?

Artificial or synthetic diamonds are (almost) impossible to distinguish from natural diamonds. They are just as beautiful, hard and brilliant as natural diamonds. The only thing they do not have...

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