Understand the stone before appreciating its value.
An independent gemmological examination, carried out rigorously, so you know what you own or what you are being offered.
Observation, loupe, microscope
Four steps of examination
Every stone follows the same path: observe, identify, verify, then give a clear opinion.
Observation & examination
Careful examination of the stone: appearance, colour, cut, surface condition, inclusions.
- Loupe observation
- Inclusion study
- Appearance and cut condition
Preliminary identification
Probable determination of species and variety from observed physical and optical properties.
- Optical properties
- Physical properties
- Signs of treatment
Documentary review
Review of existing documents and consistency of information: reports, invoices, descriptions.
- Existing reports
- Data consistency
- Points of caution
Opinion & referral
Clear findings, indicative valuation and, when justified, referral to an independent laboratory.
- Professional opinion
- Indicative valuation
- Laboratory referral
Observation, opinion, laboratory report
These notions are often confused, yet they carry different weight for a buyer or an insurer.
Gemmological observation
What is seen and measured on the stone under given conditions: colour, transparency, inclusions, accessible optical properties. A finding, not a conclusion.
Professional opinion
The interpretation of these observations: probable identification, signs of treatment, quality assessment, indicative valuation. The expert’s judgement, with its limits.
Laboratory report
Issued by an independent gemmological laboratory based on advanced instrumental analysis. Only such a report can reliably establish certain treatments, the synthetic origin of a diamond or a geographic origin.
Limits of our examinations. GemAria does not issue laboratory certificates. Its observations and opinions rely on classical gemmological methods and on the information available at the time of examination. Some treatments, some synthetics and a stone’s geographic origin can only be established by a laboratory. An indicative valuation is neither an offer to purchase nor an insurance valuation.
Expertise and trading: in full transparency
GemAria practises both expertise and trading. These principles let the buyer know exactly what a stone’s description is based on.
A report for every stone
Every stone offered by GemAria comes with its examination report, free of charge, and with the existing laboratory report where there is one.
Opinion and laboratory kept apart
The GemAria report is a professional gemmological opinion. It always says so and does not replace a laboratory report.
The laboratory chosen by the buyer
Before concluding, the buyer may have the stone tested by the independent laboratory of their choice. This additional analysis is charged separately.
Services at a stated fee
Examination on request, search or advisory: fees are given before any commitment.
What you receive
Every examination results in a written report, always structured the same way, so you know exactly what was observed and what remains to be established.
- 01
Identification of the stone
Reference, shape and cutting style, measurements, weight, existing laboratory report.
- 02
Observations
Colour, transparency, inclusions, physical and optical properties recorded, with the instruments used.
- 03
Professional opinion
Probable species and variety, signs of treatment, quality assessment.
- 04
Limits of the examination
What cannot be established without laboratory testing, stated plainly.
- 05
Recommendations
Useful further tests and, when the stakes justify it, referral to an independent laboratory.
A GemAria examination report
Extract from a real report prepared by André Lotellier for a diamond with its laboratory report. Prices and the report number are not published.
| Reference | GA · example |
|---|---|
| Laboratory report | HRD Antwerp · number given to the buyer |
| Shape and cutting style | Cushion |
| Measurements | 7.60 × 6.66 × 4.77 mm |
| Weight | 2.02 ct |
| Colour | H |
| Clarity | SI2 |
| Polish | Excellent |
| Symmetry | Very good |
| Fluorescence | Faint |
| Table | 61.0% |
| Total depth | 71.6% |
| Treatment | None, per the report |
Natural cushion-shaped diamond weighing 2.02 carats. Its H colour places it in the near-colourless range, and its SI2 clarity indicates small inclusions, sometimes visible to the naked eye. Polish is excellent and symmetry very good, with faint fluorescence.
ValuationIndicative valuation based on market references, provided to the buyer with the report.
This report is prepared by GemAria on the basis of the cited laboratory report and its own observations. It is not a laboratory certificate and does not replace the original report.
What the expertise covers
Each assignment is defined with you according to the stone, the stakes and the timeframe. The fee is given before any commitment.
- 01
Gemmological observation and examination
Careful examination of the stone and its visible features.
- 02
Preliminary identification
Probable species and variety from observed properties.
- 03
Physical and optical characteristics
Classical gemmology measurements and observations, depending on the stone.
- 04
Inclusion study
The stone’s inner world, which reveals its nature.
- 05
Visual and documentary review
Review of documents and consistency of information.
- 06
Advice on possible treatments
Signs of common treatments and recommended further testing.
- 07
Indicative valuation
An order of magnitude, with no certificate value.
- 08
Support with buying and selling
An independent opinion before concluding.
- 09
Referral to independent laboratories
Recognised laboratories, chosen according to the stone, the stakes and the target market.
Every stone has a story. Let’s discover yours.
A stone to understand, to find or to sell: write to GemAria. Every request is handled in strict confidence.