Guides

GIA, IGI, HRD — which diamond certificate actually matters?

January 2025 · 6 min read

Not all grading laboratories grade the same way. Understanding the differences could save you thousands — or explain why two identical stones are priced so differently.

When a diamond is described as ‘certified’, the word tells you something important: that an independent laboratory has examined the stone and recorded its characteristics in a standardised report. What the word does not tell you is which laboratory, or how rigorously it grades. That difference matters enormously.

What the grading difference means in practice

When comparing prices between GIA and IGI-certified natural diamonds, the apparent discount in an IGI stone often reflects the grading difference rather than a genuine bargain. Two stones may look identical on paper but may not be genuinely equivalent. This is a real market dynamic that every experienced jeweller understands.

A certificate is only as valuable as the laboratory that issued it. Buy the stone — but know whose word you are trusting.

For natural diamonds, we source GIA or HRD certified stones. For lab-grown diamonds, IGI is the appropriate standard. We will always explain the certification on any stone we present, and we will never ask you to take a grade on faith.