Diamond certification provides independent assessment of diamond quality — cut, color, clarity, carat weight. With high diamond value, certification critically determines diamond quality. There are two most prominent certification labs: Gemological Institute of America (GIA) and International Gemological Institute (IGI) in the USA, both assess and certify diamond specifications. This article examines IGI and GIA certifications and key differences to inform diamond buyers.
IGI Certification
IGI was founded in 1975, the institution has global diamond trading laboratories, leverages technological advances and diamond research in grading methodology and criteria. Reports indicate 4Cs measurements. Detail clarity characteristics and cut images. IGI is the second-largest certification lab that certifies 1 in 3 diamonds. Offers affordable, consistent global diamond certification.
GIA Certification
GIA pioneered diamond quality evaluation and the International Diamond Grading System. Stringent protocols and experienced graders. Considered global diamond certification authority. Hosts industry research and education programs. Reports detail 4Cs factors, proportions, finish, fluorescence — evaluated by independent experts. Highly valued for consistency and accuracy.
Certification Differences
Some key variances impact diamond value and pricing. GIA sets higher grading quality standards. Differences exist between color grade assessments. Cost and process duration implications. GIA certified diamonds provide higher quality assurance, but are costlier. IGI enables greater certification access across diamond markets.
Certification Selection Factors
Best certification basis use case, quality expectations and budget. GIA — high-end, high-clarity diamonds for maximum value retention. IGI offers cost-advantage for commercial quality, average diamonds. Consumer priorities: appearance, prestige value, price also matter. GIA desired for investors, IGI better value for informal jewelry.
Here is a comparison table of diamond characteristics certified by IGI and GIA:
Diamond Characteristic
IGI Certification
GIA Certification
Cut Grade
Assesses cut quality and provides cut grade
Introduced cut grading system; Most stringent cut assessments
Color Grade
Grades diamond color D-Z scale
Grades color on a D-Z scale; Slight differences in grade interpretations possible
Clarity Grade
Indicates all clarity characteristics and grades as per GIA clarity scale
Regarded as the most consistent clarity assessments; Uses GIA clarity grading scale
Polish and Symmetry
Provides polish and symmetry assessments
Considers polish and symmetry in cut grade
Fluorescence
Indicates strength of fluorescence present
Measures fluorescence strength; can impact appearance
Dimensions
Measures and indicates length, width, depth percentages
Provides length, width, depth measurements
Carat Weight
Measures and specifies accurate carat weight
Accurately measures total carat weight
Comments
Clarity characteristics indicated and described
Details all clarity characteristics present
Report Format
Includes 4Cs assessments, clarity diagram, photos, grading report #
Uses advanced technology like computer modeling for accuracy
Brand Value
Affordable pricing; accepted globally
Premium pricing; maximum brand recognition
Criticism of IGI
While IGI has established itself as one of the leading diamond certification laboratories, it has faced some criticism over inconsistencies in its grading and allegations of overgrading diamonds to benefit certain suppliers. There have been variances noted in some cases between IGI diamond grades and quality assessments when compared to other labs.
Issues like inaccurate color, clarity, or cut grades can impact diamond values. Additionally, the high-volume throughput at IGI has led to questions around maintaining grading accuracy. However, IGI has strived to improve quality control constantly through updated technology, systems, and processes.
Criticism of GIA
GIA pioneered diamond certification and grading standards, but has also encountered critique about the consistency and accuracy of its reports. Diamond grading depends heavily on human evaluation and interpretation, resulting in variances. GIA has exceptionally strict grading criteria, sometimes perceived as undergrading diamonds features. Differences in grading between two GIA reports for a same diamond have been observed in unique cases.
Additionally, the time and cost implications of certification have been cited as drawbacks. However, GIA prioritizes consumer protection through consistent analysis by multiple independent experts evaluating each diamond.
Overall, GIA grading accuracy and reliability remains widely accepted globally, despite isolated criticisms.
Conclusion
IGI and GIA use globally recognized 4Cs grading criteria. Grading philosophy differences impact pricing and value. Choice depends on individual priorities, prices, and usage. Although GIA commands premium, IGI growth and reach shows diamond quality and sparkle at varied price points.
