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Understanding an IGI Grading Report

  • You found the perfect stone now you’re staring at a wall of numbers, acronyms, and charts.
  • This guide walks you line-by-line through a typical IGI report, so you can connect the paperwork to what you’ll actually see on your hand
  • We’ll focus on lab-grown diamond reports, since that’s where IGI is most common and where you get the most value for your budget

Step 1: The Basic Info That Drives Price

  1. Report Date & Number
    1. Why it matters: verify you’re seeing the correct cert; used to look up the report online.
  2. Shape & Cutting Style
    1. Connect shapes to reader’s Pinterest/IG inspiration: oval, radiant, round, etc.
  3. Measurements
    1. Explain that dimensions affect spread on the finger, not just carat weight.
  4. The 4Cs Block
    1. Carat, Color, Clarity, Cut grade (if present) – core price drivers.
  5. Additional Information
    1. Polish, symmetry, fluorescence, inscription, and growth method (HPHT vs CVD) for lab-grown.

Da Vinci tip:

  1. If you’re comparing two IGI reports, start by lining up: carat, color, clarity, and cut. Then look at measurements and proportions to see which will actually look bigger and brighter for the price

Step 2: Proportions - How Your Diamond Handles Light

  1. Look for the section labeled ‘Proportions’ or a side-view diagram of the diamond
  2. These numbers describe how tall, deep, and wide your diamond is and how light will bounce inside it.
  3. Well-balanced proportions usually mean:
    1. Less windowing (see-through look).
    2. Less leakage (dull or dark patches)
    3. More even sparkle.
  4. Micro-checklist box – In 30 seconds, check:
    1. Depth % looks reasonable (not extremely shallow or deep for the shape).
    2. Table % isn’t extreme for that shape.
    3. Crown & pavilion angles are in a typical range (your consultant can help here we focus on real-world sparkle, not just numbers).

Step 3: Clarity Map - Where Tiny Flaws Actually Live

  1. This diagram shows the location and type of inclusions (internal) and blemishes (surface).
  2. On many IGI reports, red marks = internal, green marks = external, even if the legend isn’t printed.
  3. Don’t panic—a busy map on a larger stone can still look clean to the naked eye. What matters is:
    1. How visible they are without magnification.
    2. Whether they sit under the table (more noticeable)
    3. Whether they threaten durability (e.g., crystals on the edge)

Da Vinci Clarity Sanity Check

  • We always:
    • Inspect inclusions in standardized lighting
    • Compare the plot to actual photos and video.
    • Flag anything that might impact durability or eye-cleanliness.

Step 4: Color & Clarity Scales - Where Your Diamond Sits

  1. IGI usually prints simplified grading scales on the side of the report, so you can see where your grade falls.
  2. Color scale: D is the top of the scale (most colorless); as you move down the alphabet, warmth increases.
  3. Clarity scale: IF/FL at the top; VS and SI ranges are the sweet spot for most lab-grown shoppers great look, smarter spend.
  4. Cut grade: not always shown the same way between labs; for rounds, prioritize Cut, Polish, and Symmetry together.

Da Vinci Note

Our role is to help you find the best blend of color, clarity, cut, and budget for your story—not to chase perfection on paper.

Shop Lab Grown Diamond

Step 5: Matching the Paperwork to the Actual Diamond

  1. Many IGI reports now include:
    1. A magnified photo of the actual diamond.
    2. A photo of the laser inscription (the tiny number etched on the stone).
    3. A QR code that links to the online report.
  2. Use these to confirm:
    1. The certificate number on paper matches the number etched on the diamond.
    2. The online report matches what you’re holding.

Want a 5-minute IGI Checklist?

5-Minute IGI Checklist
Is IGI a ‘good enough’ lab?

Yes, IGI is widely respected—especially in the lab-grown space. The key is reading the report correctly and comparing apples to apples.

Lab-grown diamonds often use IGI; GIA also grades lab-grown but IGI built an early niche here. Da Vinci focuses on how consistently and transparently the stone is graded, not which logo is on top.

For most shoppers, cut and proportions (sparkle) + solid color and eye-clean clarity win over chasing perfect paper grades.

Any document can be misused, which is why we always cross-check the report number on IGI’s site and match the laser inscription on the diamond.

You may have a simplified report. Use the sections you do have and let a DVJD expert fill in the gaps with live images and video.

Yes. We’re happy to review your IGI report, explain it in plain language, and advise on settings, upgrades, or resets, no pressure to buy a new stone.

Ready to Go Beyond the Paper?

  • You now know how to read an IGI report in a way most shoppers never will.
  • The next step is seeing how your report translates to real-world sparkle, design, and budget for your story.
Shop Lab Grown Diamonds

Free 1:1 IGI Report Review

Bring your IGI report. In 20 minutes we’ll:

  • Walk through the 4Cs and proportions.
  • Flag any red-flags or over-hyped specs.
  • Suggest settings that flatter your stone.

 

Side-by-Side Diamond Comparison

Already have one IGI report? We’ll compare it to a curated shortlist of stones that match or beat it on sparkle, ethics, and value backed by our price-match guarantee, free shipping, and 30-day returns.

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