For precise, science-backed diamond assessments based on internationally recognized criteria, rely on our Diamond Grading service for complete transparency and trusted quality assurance.
Diamond Grading
At LustreStone Lab, our Diamond Grading service provides accurate, science-backed evaluations of diamonds based on internationally recognized standards. Whether for retail, investment, certification, or personal knowledge, our diamond grading reports offer complete transparency and trusted quality assurance.
With our advanced gemological equipment and highly trained gemologists, we deliver unbiased, detailed assessments to help buyers, sellers, and collectors make confident decisions in a competitive market.
Our Diamond Grading Process
1. Diamond Intake & Registration
Each diamond received is logged, securely stored, and assigned a unique identification number. We maintain strict chain-of-custody protocols to ensure integrity and traceability throughout the grading process.
2. Preliminary Inspection
Our gemologists begin with a visual inspection under controlled lighting to assess the diamond’s general characteristics, note any distinguishing features, and prepare it for detailed analysis.
3. 4Cs Evaluation
We perform a comprehensive analysis of the 4Cs — the globally accepted standard for diamond grading:
Carat Weight: Measured using high-precision scales to determine the diamond’s exact mass.
Cut: Evaluated for symmetry, proportions, and polish to determine how well the diamond reflects light.
Color: Compared against master stones under standardized lighting conditions to assign an accurate color grade (D–Z scale).
Clarity: Inspected under 10x magnification to identify and classify internal inclusions and external blemishes.
4. Advanced Testing & Verification
We use advanced gemological instruments such as spectrometers, UV fluorescence tools, and microscopes to verify natural origin, detect any treatments, and identify synthetic or lab-grown diamonds.
5. Certification & Report Issuance
Upon completion, we issue a detailed Diamond Grading Report that includes:
4Cs grades
Diamond proportions and measurements
Photomicrographs and diagrams of inclusions (where applicable)
Laser inscription details (if present)
Verification of natural origin and treatment status
6. Client Review & Consultation
We offer post-report consultations to help clients interpret the results, understand valuation implications, or plan next steps for investment, resale, or mounting.
