Diamond grading is the foundation of every smart diamond purchase. Whether you’re comparing natural or lab-grown stones, the way a diamond is graded determines how much it costs and how much it sparkles once it’s on your finger. The trouble is, grading isn’t always straightforward. Different labs have different standards, some tools are helpful while others mislead and the rules themselves can shift overnight.
A perfect example is GIA’s recent decision to withdraw from full grading of lab-grown diamonds starting October 1, 2025. Instead of offering detailed cut, color and clarity reports, GIA now limits lab-grown diamonds to a simplified classification of Premium and Standard. This change sent shockwaves through the industry and shows just how important it is to stay informed about who’s grading your diamond and what those grades really mean.
On this page, I’ve collected all of my guides on diamond grading into one place. From understanding polish and symmetry (which are separate grades and not part of cut as many people mistakenly believe) to evaluating Hearts & Arrows diamonds and navigating GIA vs IGI reports, this hub is designed to give you clarity in a space where confusion is common. Use it as your starting point, then dive deeper into the sections that matter most for your diamond search.
Diamond Grading Basics
- Best Diamond Labs: Overview of the major grading labs, their differences and which ones you can trust.
- 23 Key Diamond Grading Questions: A Q&A format guide that answers the most common concerns buyers have.
- How to Read a Diamond Grading Report: Step-by-step guide to understanding every part of a grading report.
Lab Updates & Industry Shifts
- GIA Withdraws from Lab-Grown Diamonds: Why GIA stopped grading lab-grown diamonds and what it means for buyers.
- GIA vs IGI: A side-by-side comparison of the two most important labs.
- Diamond Certification Guide (GIA vs IGI vs GCAL vs HRD): Full overview of how all the major labs compare today.
Cut & Light Performance
- Hearts & Arrows Diamonds: How super ideal cut diamonds are graded and what those arrows actually mean.
- Diamond Contrast and Brilliance: How dark and light zones create sparkle.
- Holloway Cut Advisor Cons: Why the HCA is not as useful anymore.
Polish & Symmetry
- Diamond Polish: What it really means in grading reports and how it affects sparkle.
- Diamond Symmetry: How symmetry grades work and when you should care.
- Diamond Cut vs Polish vs Symmetry: Why cut is seperate and how all three grades interact.
Your Roadmap
Understanding grading is the first step toward buying a diamond with confidence. From my perspective, too many shoppers get caught up in single grades or chase numbers without realizing how the whole picture comes together. A diamond report is only as good as the lab behind it and even then you need to know what really matters for sparkle and value.
If you want the safest path start by trusting a top lab, learn how cut quality drives brilliance and only then fine tune with polish, symmetry and other details. Think of grading as a map that guides you to the right diamond, not as a rulebook that decides for you.
I suggest using this hub as your reference point. Explore the guides linked here, then connect what you learn with the four Cs of diamonds, cut, color, clarity and carat. Once you see how grading fits into the bigger picture you will make choices with far more confidence and avoid the mistakes most buyers make.