Reading GIA Certificates: What do the specifications mean?

GIA Certificate: The most important document when buying a diamond

Being able to read a GIA certificate is one of the most important skills when buying a diamond. This document from the Gemological Institute of America independently confirms all relevant characteristics of the stone.

What the GIA certificate confirms

• Shape and Cutting Style: Cut shape (Round, Oval, Princess etc.)
• Measurements: Dimensions of the stone in mm
• Carat Weight: Weight in carats (1 carat = 0.2 grams)
• Color Grade: Color grade from D (colorless) to Z (yellowish)
• Clarity Grade: Clarity from FL (flawless) to I3 (heavily included)
• Cut Grade: Cut quality from Excellent to Poor (only for round brilliants)

Understanding the color scale

• D-F: Completely colorless – highest category
• G-J: Nearly colorless – indistinguishable from D-F with the naked eye
• K-M: Slightly yellowish – visible without comparison

Understanding the clarity scale

• FL/IF: Flawless – no inclusions under 10x magnification
• VVS1/VVS2: Very difficult to see inclusions
• VS1/VS2: Small inclusions – only visible under a loupe
• SI1/SI2: Small inclusions – sometimes visible with the naked eye

Check GIA number

The GIA certificate has a number (Report Number). This is microscopically laser inscribed on the girdle (edge area) of the stone. This way, you can 100% match the certificate and the stone.

Only GIA-certified diamonds at corelunejewellery.de – all certificates verifiable online.