Using GemID — App Guide
GemID identifies gemstones by physical properties. Enter measurements; the app filters candidates and suggests the next most useful test.
Expert Mode
Expert mode shows all 15 input sections at once. An orange dot marks the section with the highest-value next test — follow the dot and take that measurement first. Toggle expert mode in the top-right menu.
Without expert mode, the app presents sections one at a time in the guided wizard sequence. Both modes use the same underlying engine; expert mode is faster for experienced gemologists who already have multiple measurements ready.
How Identification Works
Enter a measurement
Tap a section to expand it and enter your reading — refractive index, specific gravity, fluorescence response, or any other property you have.
Candidate list updates instantly
GemID filters all 130 gem species against your inputs in real time. Eliminated gems move to the bottom with the reason they were ruled out.
The orange dot moves to the next best test
After each entry, the engine recalculates which measurement would eliminate the most remaining candidates. The orange dot marks that section.
Repeat until one or two candidates remain
Most unknowns resolve to one or two candidates after RI + SG. Fluorescence and optic character close the remaining gap.
Input Sections
Each section collapses when not in use. Enter only what you have — all fields are optional.
- Color — body color, saturation, and distribution
- Refractive Index — RI min/max; birefringence calculated automatically
- Birefringence — enter directly if measured from interference figure
- Optic Character — SR, DR uniaxial +/−, DR biaxial +/−, isotropic
- Specific Gravity — measured by hydrostatic weighing
- Fluorescence (LW/SW) — longwave and shortwave UV response and color
- Pleochroism — none, weak, moderate, strong; colors observed
- Luster — adamantine, vitreous, resinous, pearly, silky
- Crystal System — cubic, tetragonal, hexagonal, trigonal, orthorhombic, monoclinic, triclinic
- Transparency — transparent, translucent, opaque
- Inclusions — observed inclusion types as diagnostic indicators
- Phenomenon — asterism, chatoyancy, color change, adularescence
Reading Results
Candidates are ranked by how consistently their published property ranges match your inputs. Eliminated gems move to the "Eliminated" list with the property that ruled them out.
The Next Test chip at the top of the results names the one measurement that would eliminate the most remaining candidates. This updates after every input.
Results show what a stone is consistent with — not a certified identification. A gemological laboratory report is required for certification.
Gem Properties Detail
Tap Properties on any candidate card to see the full reference entry — optical properties, physical constants, diagnostic tests, known synthetics, common treatments, and a market value guide.
Natural vs. Synthetic Testing Pro
A two-phase protocol for origin determination. Phase 1 identifies origin indicators: Chelsea filter reaction, fluorescence pattern, spectral characteristics, and inclusion morphology. Phase 2 tests for specific treatments relevant to the species.
Available for 33 species with known synthetics — from corundum (ruby, sapphire) to emerald to alexandrite. Access the nat/syn protocol from the identification results screen after a candidate has been identified.
Saving & Reports Hobbyist+
Save identification sessions with notes, client information, and photos. Saved sessions are stored to your account and accessible across devices.
Pro subscribers can export examination reports as PDFs — formatted with all entered properties, candidate results, and session metadata suitable for client records.
Building a Report
Select stones from any client or collection, choose the output format (PDF, HTML, JSON, XML, or CSV), and send directly by email. Reports include all entered observations, candidate identities, and session metadata.
Report Output
Generated reports are formatted as professional examination records — specimen name, all recorded observations, candidate identities, and the observations that confirmed the identification.
Collection Stats Hobbyist+
Collection statistics summarize your saved stones by color, gem family, and origin/treatment status. Useful for tracking what you've identified across clients and lots.
Ready to identify? Open GemID in your browser or download the iOS/Android app.
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