Digital carat scale
Measures the gemstone’s weight in carats. Weight helps describe the specimen and can be considered with its dimensions and other properties.
A closer look at the work
A report is only as useful as the evidence behind it.
Gemstone identification is a sequence of careful observations and, where appropriate, measured tests. We bring those findings together, explain what they support, and note where the evidence has limits.
01 — From receipt to report
A considered sequence
Each step adds context to the next. The exact tests used depend on the stone and what can be examined safely.
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01
Receipt, intake & documentation
We record the submitted item and the information provided, then document its condition and visible features before testing. Customer photos are optional, but recommended as helpful context.
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02
Measurements
Weight and dimensions are measured where the form of the specimen permits. Measurements are recorded as observations, not treated as identification on their own.
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03
Visual and microscopic observation
Appearance, transparency, cutting, surface features, and internal characteristics are examined under suitable lighting and magnification.
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04
Optical and physical testing
Applicable instruments are selected for the specimen. A result is considered alongside other observations; a test may be omitted when contact, condition, or mounting makes it unsuitable.
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05
Evidence review & limitations
Findings are compared for consistency. Treatment or geographic origin is reported only when supported by the methods and evidence available; either may remain undetermined.
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06
Photography & digital report
Photographs document the examined gemstone. The resulting digital identification report summarizes the supported findings and can be checked through online report verification.
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07
Return arrangements
After examination and reporting, return arrangements are coordinated with the customer. Please contact PGL if you need to confirm arrangements for a particular submission.
02 — Instruments & what they tell us
Different tools, distinct questions.
These instruments contribute observations. None is presented as standalone proof of identity, treatment, or origin.
Measurement
Digital calipers
Record dimensions such as length, width, and depth where accessible. Shape, setting, and proportions can affect what can be measured.
10× jeweler’s loupe
Provides standard hand magnification for examining facets, surface details, and visible inclusions.
Gemological microscope
Offers greater magnification and controlled illumination to inspect internal features, growth structures, and surface characteristics.
Refractometer + RI fluid
Measures refractive index on a suitable polished surface. Contact and fluid are not appropriate for every gemstone or surface, so this test is used only when suitable.
Polariscope
Shows how a gemstone behaves between crossed polarizing filters, helping assess optical character and strain patterns.
Dichroscope
Separates light into directional color views, which can reveal pleochroism in suitable transparent gemstones.
Specific gravity testing kit
Supports density comparison through specific gravity measurement when safe and applicable to the specimen. It is not used when the method could be unsuitable.
Long-wave UV lamp (365 nm)
Provides a controlled long-wave ultraviolet observation of fluorescence response. A response, or lack of one, is a clue—not proof.
Short-wave UV lamp (254 nm)
Provides a separate short-wave ultraviolet observation. Results are interpreted with care and alongside other evidence, never as a standalone identification.
Handheld gemological spectroscope
Allows visual observation of selected absorption features in transmitted light. This is a handheld gemological tool, not an advanced laboratory spectrometer.
Chelsea filter
A selective filter can show color responses useful in some comparisons. It is a screening observation and cannot establish identity by itself.
Standardized daylight lamp
Provides consistent viewing illumination for assessing and documenting color. Lighting supports comparison; it does not determine identity.
Gemstone photography camera
Creates clear visual documentation of the gemstone and relevant details for its report. Images complement, rather than replace, examination.
A note on conclusions
Good analysis includes knowing what a test cannot say.
Some measurements or contact tests may not be appropriate for a particular stone. RI fluid, specific gravity, UV response, and filter observations each have limits. Treatment and geographic origin are stated only when supported by available methods and evidence; they are not always determinable. No single observation is treated as conclusive proof.
One clear service
Comprehensive Gemstone Identification
Customer photos are optional, but recommended to provide context for intake.
$50per stoneEstimated 5–7 business days
Submit a gemstone