The methodology, applied

Worked examples on real stones

Four GIA certified diamonds observed on the live market, scored step by step. Every certificate number below can be verified on GIA Report Check. Quality and certification components are shown exactly as the engine computes them.

GIA 1547371080

GIA 1547371080: 1.02 ct Oval, E VVS1

Verify this certificate on GIA Report Check using report number 1547371080.

Quality components
ComponentInputScoreWeight
Cut EX 95 25
Color E 96 20
Clarity VVS1 92 18
Proportions 60 / 62 100 12
Polish EX 95 8
Symmetry EX 95 8
Fluorescence NON 100 5
Culet NON 100 2
Girdle MED-THK 80.5 2
A+
Quality score: 95.3 (Exceptional)
Data coverage: 100% of weighted evidence present

Certification score: 95.2

Certification components
ComponentScoreWeight
Laboratory reputation10040
Data completeness9840
Certificate availability8020
GIA 1559424613

GIA 1559424613: 0.8 ct Round, F SI1

Verify this certificate on GIA Report Check using report number 1559424613.

Quality components
ComponentInputScoreWeight
Cut EX 95 25
Color F 92 20
Clarity SI1 60 18
Proportions 56 / 63.2 98.6 12
Polish EX 95 8
Symmetry VG 75 8
Fluorescence STR 40 5
Culet NON 100 2
Girdle THN-STK 77 2
A
Quality score: 83.9 (Excellent)
Data coverage: 100% of weighted evidence present

Certification score: 91.6

Certification components
ComponentScoreWeight
Laboratory reputation10040
Data completeness8940
Certificate availability8020
GIA 7426477593

GIA 7426477593: 1 ct Round, J SI2

Verify this certificate on GIA Report Check using report number 7426477593.

Quality components
ComponentInputScoreWeight
Cut EX 95 25
Color J 64 20
Clarity SI2 50 18
Proportions 57 / 62.9 99.2 12
Polish EX 95 8
Symmetry EX 95 8
Fluorescence NON 100 5
Culet NON 100 2
Girdle THK 70 2
A
Quality score: 81.1 (Excellent)
Data coverage: 100% of weighted evidence present

Certification score: 96

Certification components
ComponentScoreWeight
Laboratory reputation10040
Data completeness10040
Certificate availability8020
GIA 2221158293

GIA 2221158293: 0.7 ct Round, M SI1

Verify this certificate on GIA Report Check using report number 2221158293.

Quality components
ComponentInputScoreWeight
Cut FR 25 25
Color M 35 20
Clarity SI1 60 18
Proportions 66 / 59.2 84 12
Polish EX 95 8
Symmetry GD 50 8
Fluorescence MED 70 5
Culet NON 100 2
Girdle VTK 40 2
C
Quality score: 52 (Average)
Data coverage: 100% of weighted evidence present

Certification score: 95.2

Certification components
ComponentScoreWeight
Laboratory reputation10040
Data completeness9840
Certificate availability8020

Value and market scores are omitted here because they move with the live market; the stones above are scored on their stone level pillars only. See the full methodology for the market side.