Lifetime free cleaning and polishing service.

Free insured shipping in Europe.

Your cart

Your cart is empty

Bekijk deze collecties.

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

Discover your ring size

Measure an existing ring Measure your finger

Your Enquiry

Your Enquiry




Your perfect proposal

Under the enchanting canopy of a thousand twinkling stars, the couple found themselves strolling through the lush gardens of a historic castle they had rented for the weekend.

The soft glow of lanterns illuminated their path, guiding them to a secluded spot where a small table, adorned with roses and flickering candles, awaited them.

As they sipped champagne and reminisced about their journey together, a string quartet hidden nearby began to play their favorite song.

Overwhelmed with emotion, they locked eyes, and with a heart full of love, one partner slowly dropped to one knee.

Producing a delicate blue box, they opened it to reveal a dazzling ring, and with a voice trembling with excitement, asked for their beloved's hand in marriage.

The moment was pure magic, a perfect proposal that would be cherished forever.

Unveil Your Perfect Proposal

A Quick 2-Minute Quiz to Inspire You for the ultimate question

We understand that planning the perfect proposal can be a challenge. That's why we've developed a special quiz to help our customers find the ideal setup for their marriage proposal. Our quiz takes you through a series of carefully curated questions that provide insight into your unique preferences and your partner's desires. At the end of the quiz, you'll receive personalized recommendations for an unforgettable proposal tailored to your individual style and situation.

Let us guide you in creating a magical moment that both of you will cherish forever.

The Do's & Don't for your perfect proposal

It's essential to recognize that etiquette can vary significantly depending on cultural backgrounds and individual preferences, rather than race. When planning a marriage proposal, it's crucial to consider the cultural customs and traditions of your partner and their family. Here are some general guidelines for a few cultural backgrounds:

Western Cultures

  • Get to know your partner's preferences and tastes.

  • Consider asking for the parents' blessing, although not always required.

  • Choose a meaningful location or setting.

  • Make the proposal personal and heartfelt.

Chinese Cultures

  • Consult with a fortune teller or astrologer to find an auspicious date.

  • Ask for the parents' permission and blessings.

  • Consider incorporating traditional symbols, such as the color red, into the proposal.

Indian Cultures

  • Seek the parents' blessings and approval.

  • Incorporate traditional customs, such as exchanging gifts or sweets.

  • Consider proposing during a significant festival or family gathering.

Japanese Cultures

  • Ask for the family's permission and blessings.

  • Choose a private and intimate location for the proposal.

  • Present the engagement ring in a beautifully wrapped box.

Middle Eastern Cultures

  • Seek the parents' approval and blessings.

  • Be respectful of religious customs and expectations.

  • Consider proposing in a private and intimate setting.

African Cultures

  • Consult with the family and seek their approval.

  • Respect the traditions and customs of your partner's specific cultural background.

  • Consider incorporating traditional elements, such as music or clothing, into the proposal.

The "better not's"


While not all proposals require a ring, it's a widely accepted symbol of commitment. If you plan to present one, make sure you have it with you.


Ensure that you and your partner have had enough time to get to know each other and have discussed your future together before proposing.


Unforeseen circumstances can arise, such as bad weather or a change in venue. Be prepared with a backup plan to ensure the proposal goes smoothly.


Take your time during the proposal, and don't rush through your words or actions. This is a significant moment for both of you, so savor it.


Rehearse what you want to say and how you want to present the ring. This can help reduce nerves and ensure a smoother proposal.


Be aware of any cultural or religious customs that may be relevant to your partner and their family, and plan your proposal accordingly.

Remember, the most important aspect of a marriage proposal is that it reflects the love and commitment you share with your partner. Keep their preferences and feelings in mind as you plan and execute the proposal.


The engagement collection

Experience our Royal Service both Online and In-Person at Our Flagship Store

The Royal Coster Diamonds Experience

At our esteemed jewelry establishment, with over 175 years of experience and a prime location in the heart of Amsterdam's Museum Square, we appreciate the advantages of purchasing jewelry online.

When you choose to buy a diamond engagement ring from our online store, you enjoy the convenience and flexibility of shopping from the comfort of your own home while still benefiting from our strong legacy and unwavering commitment to service.

Our exceptional online platform allows you to browse and compare an extensive selection of exquisite designs at your own pace, without any pressure.

Additionally, our dedicated team of experts is readily available to assist you, both online and offline, ensuring that you receive the same personalized guidance and support that has distinguished our brand for nearly two centuries.

Embrace the modern approach to purchasing a symbol of your love, backed by a heritage of excellence and trust.

Royal Coster Diamonds

The Engagement collection