Laboratory Reports
Understanding gem laboratory reports from GIA, Gübelin, SSEF, GRS, and other major labs with terminology, grading, and certification.
By Fabian Moor
Last updated
market/lab-reports certification gia gubelin ssef
Introduction
A gemological laboratory report is an independent technical document confirming a
stone's species identity, natural or synthetic origin, treatment status, and (for
premium material) geographic provenance. Its commercial role is to convert
subjective seller claims into verifiable, insured facts. The leading laboratories
for coloured stones are Gübelin Gem Lab and SSEF in Switzerland, both of which set
the international benchmark for ruby and sapphire origin determination;
[1][2] GIA reports are the dominant
standard for diamonds and carry broad global recognition since the institute's
founding in 1931. [3] GRS popularised the descriptive
colour designations "pigeon's blood" and "royal blue", which now appear as premium
qualifiers on trade invoices and auction catalogues. [4]
Because counterfeit reports circulate, every report should be verified through the
issuing laboratory's online portal before a purchase is completed.
[5]
Purpose of Lab Reports
Why laboratory certification matters:
What Labs Verify
- Species identification: Confirms what the gem actually is
- Natural vs synthetic: Distinguishes natural from lab-grown
- Treatment status: Discloses any enhancements
- Origin determination: Geographic source (advanced analysis)
- Quality grades: Some labs grade colour, clarity, cut
Major Gemological Laboratories
Leading laboratories for coloured stones:
Gübelin Gem Lab
- Location: Lucerne, Switzerland [1]
- Founded: 1923
- Strengths: Origin determination, coloured stones
- Reputation: Highest tier; premium market acceptance
- Notable: Pioneered modern origin determination
SSEF
- Full name: Swiss Gemmological Institute [2]
- Location: Basel, Switzerland
- Founded: 1972
- Strengths: Research-based; coloured stones; pearls
- Reputation: Top tier; widely accepted
GIA
- Full name: Gemological Institute of America [3]
- Location: Carlsbad, California (HQ); global labs
- Founded: 1931
- Strengths: Diamonds (created 4Cs); coloured stones
- Reputation: Excellent; most recognised globally
GRS
- Full name: GRS GemResearch Swisslab
- Location: Switzerland and Asia offices
- Founded: 1990s
- Strengths: Coloured stones; colour terminology
- Notable: Created "pigeon blood" and "royal blue" grades [4]
Laboratory Comparison
| Lab | Headquarters | Specialties | Market |
|---|---|---|---|
| Gübelin | Switzerland | Origins, coloured stones | High-end trade |
| SSEF | Switzerland | Research, pearls, colours | High-end trade |
| GIA | USA (global) | Diamonds, all gems | Universal acceptance |
| GRS | Switzerland/Asia | Colour grades, origins | Asian markets strong |
| Lotus Gemology | Thailand | Thai/Burma material | Regional; growing |
| AGL | USA | Coloured stones | US trade |
| C. Dunaigre | Switzerland | Origins, colours | Trade professionals |
Report Components
What a typical coloured stone report includes:
Basic Information
- Report number: Unique identifier for verification
- Date: When examination was performed
- Weight: Carat weight (usually to 0.01ct)
- Dimensions: Length × width × depth in mm
- Shape/cut: Faceted, cabochon, or other
Identification
Treatment Status
- Treatment detected: What modifications found
- Degree/extent: Minor, moderate, significant
- Stability: Permanent vs potentially unstable
Origin (When Offered)
- Geographic origin: Country or region
- Confidence level: "Origin determination" vs "origin opinion"
- Supporting evidence: Inclusion suite, chemistry
Report Verification
Treatment Terminology
Standard treatment designations:
Heat Treatment
| Term | Meaning |
|---|---|
| No indication of heating | Unheated (premium) |
| Indications of heating | Heat treated (routine for many gems) |
| Low-temperature heating | Gentle heat; less modification |
| High-temperature heating | More significant changes |
Clarity Enhancement (Emerald)
| Term | Meaning |
|---|---|
| None | No filling detected (highest value) |
| Minor/Insignificant | Minimal treatment (small discount) |
| Moderate | Noticeable treatment (moderate discount) |
| Significant | Extensive treatment (substantial discount) |
Other Treatments
- Beryllium diffusion: Adds element to change colour [6]
- Glass/lead filling: Fracture filling (major disclosure)
- Coating: Surface treatment (typically unacceptable)
- Irradiation: Colour modification by radiation
Origin Terminology
How labs express origin confidence:
Confidence Levels
- "Origin: Kashmir": High confidence
- "Origin opinion": Moderate confidence; supporting evidence
- "No origin determination possible": Characteristics overlap
- "Consistent with...": Lower confidence; indicative only
Why Origin Is Difficult
- Many deposits share characteristics
- Some stones show mixed features
- Heat treatment can alter origin indicators
- Research ongoing; methods improving
- Different labs may reach different conclusions
Colour Grading Systems
Laboratory colour terminology:
GRS Colour Grades
GIA Colour Description
- Hue (spectral colour)
- Tone (light to dark)
- Saturation (intensity)
- Descriptive terminology, not single grades
Standardisation Efforts
- LMHC harmonises terminology [7]
- Not all labs participate equally
- Trade terms may differ from lab terms
- Understanding each lab's system important
Reading a Report
Practical interpretation guide:
Key Questions to Answer
- Is the stone natural or synthetic?
- What treatments have been applied?
- Is origin claimed and well-supported?
- Does the weight match the actual stone?
- Is the report number verifiable?
Red Flags
- Origin claimed without clear supporting evidence
- Unclear treatment status or evasive language
- Report from unknown or unaccredited lab
- Discrepancies between report and stone
- Report number fails online verification
Best Practices
- Match report to actual stone carefully
- Verify report online before purchase
- Understand what the lab does and doesn't claim
- For very high values, consider second opinion
- Keep original reports secure; copies for display
Cost Considerations
Laboratory report costs and timing:
- Basic identification: $50-150
- Full report with origin: $100-500+
- Rush services: Additional premium
- Turnaround: Days to weeks depending on lab/service
- Value threshold: Reports typically worthwhile >$1,000 stones
References
- ↑ 1. Gübelin, E.; Koivula, J. (1986). Photoatlas of Inclusions in Gemstones (1 ed.). ABC Edition. ISBN: 978-3-85504-024-2.
- ↑ 2. Swiss Gemmological Institute (SSEF) (1972). About SSEF: History and Research. Swiss Gemmological Institute. Retrieved 2026-05-11, from https://www.ssef.ch/about/
- ↑ 3. Gemological Institute of America (1931). About GIA: History. Gemological Institute of America. Retrieved 2026-05-11, from https://www.gia.edu/about-GIA/history
- ↑ 4. GRS GemResearch Swisslab (2004). GRS Type Colour Reference: Pigeon Blood Ruby Criteria. GRS GemResearch Swisslab. Retrieved 2026-05-11, from https://www.grs.ch/en/reports/colour-grades
- ↑ 5. Gemological Institute of America (2007). GIA Report Check. Gemological Institute of America. Retrieved 2026-05-11, from https://www.gia.edu/report-check
- ↑ 6. Emmett, J.; Scarratt, K.; McClure, S.; Moses, T.; Douthit, T.; Hughes, R.; Novak, S.; Shigley, J.; Wang, W.; Bordelon, O.; Kane, R. (2003). Beryllium Diffusion of Ruby and Sapphire. Gems & Gemology, 39(2), 84–135. DOI: 10.5741/gems.39.2.84.
- ↑ 7. Laboratory Manual Harmonisation Committee (2010). LMHC Standards and Terminology for the Description of Treatments in Coloured Gemstones. LMHC. https://www.lmhc-gemmology.org.
- ↑ 8. Shor, R.; Weldon, R. (2009). Ruby and Sapphire Production and Distribution: A Quarter Century of Change. Gems & Gemology, 45(4), 236–259. DOI: 10.5741/gems.45.4.236.