How to Read a Diamond Certificate Like a Master Gemologist
Your grading report is your stone's official pedigree. Here's how to decode table %, depth %, polish, symmetry, and what actually dictates brilliance.
Your grading report is your stone's official pedigree. Here's how to decode table %, depth %, polish, symmetry, and what actually dictates brilliance.
Every certified diamond in the Lucent Carat vault includes an independent certificate from IGI or GIA. While the document contains over twenty optical measurements, five critical sections govern its true quality and brilliance.
1. Report Number and Inscription Registry At the top sits a unique alphanumeric report number. This number is micro-laser inscribed onto the diamond's girdle and is verifiable 24/7 on the official IGI or GIA international registry database.#
2. The 4Cs Graded Hierarchy Cut, Colour, Clarity, and Carat Weight represent the universal grading standard. Cut grade (Ideal or Excellent) is the paramount specification, governing light return, scintillation, and fire.#
3. Optical Proportions & Angles - **Table Percentage**: Optimal between 54% and 60% for Round and Oval cuts. - **Depth Percentage**: Optimal between 59% and 62.5% for maximum light refraction without light leakage. - **Polish & Symmetry**: Look for 'Ideal' or 'Excellent' to guarantee crisp mirror-finish facets.#
4. Fluorescence Ratings Fluorescence refers to how a diamond reacts under UV light. For lab-grown diamonds, 'None' or 'Faint' ensures an ultra-crisp, crystal-clear appearance with zero haziness.#
Frequently Asked Questions
IGI is the global pioneer and market leader in lab-grown diamond grading, evaluating over 85% of certified stones with detailed 4Cs specifications. GIA also grades lab stones using identical criteria.
Priya Nair, GG
Author & GemologistWritten and curated by Lucent Carat’s gemological team. We combine independent laboratory grading (IGI & GIA) with manufacturer-direct pricing to empower confident diamond buying.
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