Order before Feb. 10th and get it before Valentine's.

Free shipping and insured in Europe.

Lifetime free cleaning and polishing.

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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.
Tours & workshops - Royal Coster Diamonds

Tours & workshops

Discover the magical world Of Diamonds

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.

Free guided 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.

the royal experience

Experience diamonds like the Royals did during our Royal Experience. See diamond polishers and goldsmiths at work while your personal guide explains the origin of diamonds and why we are number 1 choice for diamonds.

the diamond masterclass deluxe

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!

The engagement workshop

This workshop is for couples who are preparing for an engagement or anniversary and want to learn more about diamonds and diamond rings before they purchase. Learn everything with us.

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?