Diamond & Gemstone Grading Services
Standardized evaluation of physical optical parameters, color grade, clarity, cut geometry, and carat weight.
Systematic Quality Evaluation
IGL grading services provide structured assessment reports tailored to specific gemstone and diamond material classes.
Diamond 4Cs Evaluation
Evaluated under controlled daylight-equivalent conditions and 10x magnification:
- Color Grade: D to Z scale comparison using calibrated master diamonds.
- Clarity Grade: Flawless to Included (FL, IF, VVS1-VVS2, VS1-VS2, SI1-SI2, I1-I3).
- Cut Proportions: Table %, Crown angle, Pavilion depth, Girdle thickness, Polish, Symmetry.
- Carat Weight: Measured using micro-balances accurate to 0.001 carats.
Gemstone Quality Parameters
Colored gemstones are evaluated based on material-specific quality factors:
- Color Characteristics: Primary Hue, Tone (light to dark), Saturation (vibrancy).
- Clarity / Transparency: Eye-clean, slightly included, moderately included, opaque.
- Cut & Polish: Facet symmetry, brilliance, windowing, extinction.
- Carat Weight & Dimensions: Precise millimeter measurements and gram/carat weight.
Standardized Assessment Based on Material Type
Grading parameters are tailored to the specific mineral species submitted. Diamonds follow standardized 4Cs evaluation criteria, whereas colored gemstones (rubies, sapphires, emeralds) are evaluated taking into account species-inherent inclusion patterns and color saturation norms.
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