Loose diamonds and a gold ring held with tweezers on a neutral surface
Diamond Guide

Choose the right
diamond, with clarity.

OnlyRock helps you understand lab-grown diamonds, cut, size, quality and certification so you can make a confident choice that feels right for you.

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Lab-grown diamonds
Clear guidance
Independently graded
Personal sourcing
How We Help You Choose

We don't overwhelm you with thousands of listings. Instead, we listen to what matters to you—cut, size, design and budget—and shortlist diamond options that truly suit your vision.

1. Tell us your preferences
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2. Review current options
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3. Compare reports & visuals
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4. Choose with confidence

The 4Cs of Diamond Quality

The global standard for evaluating diamond quality.

Different Cut, Different Brilliance

Find the Cut That Speaks to You

Diamond Size Guide

How size looks in real life.

Diamond size comparison from 0.25 to 3.00 carat, shown on hand
Appearance can vary by cut, carat weight and setting.

How to Choose
the Right Diamond

There is no “perfect” diamond — only the perfect diamond for you. Consider your priorities, budget and the story you want your diamond to tell.

  • Prioritise Cut for brilliance
  • Balance the 4Cs within your budget
  • Choose a shape that reflects your style
  • Buy from a trusted source
Read the Full Guide
Loose round, emerald and marquise diamonds beside an OnlyRock jeweller's loupe and ring