Laboratory Reports
Understanding gem laboratory reports from GIA, Gübelin, SSEF, GRS, and other major labs with terminology, grading, and certification.
market/lab-reports certification gia gubelin ssef
Introduction
Laboratory reports provide independent verification of a gemstone's identity,
natural or synthetic origin, treatments, and sometimes geographic origin.
Understanding lab reports is essential for trade and high-value purchases.
Different laboratories have varying strengths, methodologies, and market
recognition. Report quality directly affects gem value and confidence.
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
- Founded: 1923
- Strengths: Origin determination, coloured stones
- Reputation: Highest tier; premium market acceptance
- Notable: Pioneered modern origin determination
SSEF
- Full name: Swiss Gemmological Institute
- Location: Basel, Switzerland
- Founded: 1972
- Strengths: Research-based; coloured stones; pearls
- Reputation: Top tier; widely accepted
GIA
- Full name: Gemological Institute of America
- 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
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
- 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
- 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