GemID App Guide — How to Identify Gemstones

How Identification Works

GemID uses the same property-based workflow gemologists rely on. Enter measurements one at a time; the engine filters all 130 gem species against your inputs and ranks which test to run next.

1

Enter an observation

Start with what you can see — body color, transparency, luster. Tap a chip to select it. Every field is optional; enter only what you have.

2

Candidates update in real time

The progress bar shows how many of the 130 gems remain consistent with your inputs. Eliminated gems are sorted by how close they came, with the specific property that ruled them out.

3

Follow the suggested next test

GemID calculates which measurement would split the remaining candidates most effectively and suggests it at the top of the screen. Follow the suggestion for the fastest path to identification.

4

Repeat until identified

Most unknowns resolve after RI + SG + optic character. Fluorescence and inclusions close the remaining gap. When one gem remains, the app shows a conclusion.

Tip: You don’t need every instrument. Start with visual observations (free, no equipment needed), then add refractometer and hydrostatic readings. Most identifications resolve with 3–5 measurements.

GemID identify screen showing 7 observations entered, 6 of 130 gems remaining, with suggested next test

Entering Observations

Observations are organized into collapsible sections on the Observations tab. Tap any section to expand it. Visual properties use chip selectors; instrumental measurements use numeric inputs with built-in range validation.

Visual Observations (no equipment needed)

Body Color — 10 categories: colorless, red/pink, blue/violet, green, yellow/orange, brown, purple, black, color-change, multi
Transparency — transparent, translucent, opaque
Luster — adamantine, vitreous, resinous, waxy, metallic, pearly, silky
Phenomena — asterism, chatoyancy, adularescence, labradorescence, play of color, aventurescence

GemID observation chips showing color categories, transparency, and luster options

Instrument Measurements

Refractive Index (RI) — refractometer reading; ±0.010 tolerance for faceted, ±0.020 for cabochons. Over-the-limit (OTL) supported for high-RI gems.
Specific Gravity (SG) — hydrostatic weighing; ±0.10 tolerance
Birefringence — enter directly or let GemID calculate from RI min/max
Optic Character — SR, DR uniaxial ±, DR biaxial ±, ADR, aggregate. Determined with polariscope + conoscope.
Fluorescence (LW & SW) — longwave and shortwave UV response. Select intensity + color.
Pleochroism — none through strong trichroic; observed with dichroscope
Spectroscope — select observed absorption pattern (chromium doublet, almandite trio, etc.) or describe what you see
Chelsea & Hanneman filters — color reaction through diagnostic filters
Thermal tester — diamond vs. simulant probe result

Physical Properties

Inclusions (loupe & darkfield) — multi-select observed types (silk, needles, fingerprints, gas bubbles, etc.)
Hardness — Mohs scratch test result
Cleavage & fracture — observed break characteristics
Crystal habit — observed crystal form (octahedral, prismatic, tabular, etc.)

Help Text

Tap the ? icon next to any observation to see what to look for, how to take the measurement, and what each outcome means for your identification.

Reading Results

Switch to the Candidates tab to see which gems match your observations. Each candidate card shows the gem name, optic character, RI/SG ranges, and key properties at a glance.

GemID candidates tab showing Padparadscha Sapphire with properties, next test suggestions, and save button

GemID diamond identification showing market context with natural and synthetic pricing

What Each Card Shows

Best Next Tests — the top two tests that would eliminate the most remaining candidates
Gem name & optic character — species, variety, and SR/DR/AGG classification
Property ranges — RI, SG, birefringence so you can compare your reading directly
Properties button — full reference entry with all published data for that gem
Stone Type Test Pro — run the natural vs. synthetic origin protocol
Market Context Pro — approximate per-carat pricing for natural and synthetic, plus how treatments affect value

Eliminated Gems

Tap the “N eliminated” button below the progress bar to see every gem that was ruled out and exactly which measurement eliminated it. Sorted by closest match first — useful for checking borderline cases.

No Match

If no gems match, GemID shows the closest misses with the specific reading that ruled them out. Double-check your measurements against the expected ranges shown. Common causes: transposed RI digits, SG measured on a set stone, or a synthetic not in the database.

GemID showing 0 of 130 gems remaining with all eliminated

Important: Results show what a stone is consistent with — not a certified identification. A gemological laboratory report (GIA, AGL, Gübelin, etc.) is required for formal certification.

Natural vs. Synthetic Testing Pro

Once a gem species is identified, the origin protocol helps determine whether the stone is natural, lab-grown, or treated. Available for 33 species with known synthetics — from corundum (ruby, sapphire) to emerald, diamond, spinel, and alexandrite.

Two-Phase Protocol

1

Origin Determination

Guided step-by-step tests for origin indicators: Chelsea filter reaction, fluorescence pattern, spectral characteristics, and inclusion morphology. Each step shows what to look for and what each outcome means.

2

Treatment Detection

Tests for species-specific treatments: heat treatment in corundum, fracture filling in emerald, irradiation in topaz, diffusion in sapphire, and more. Results indicate which treatments are consistent with your observations.

Access the protocol from any candidate card by tapping Stone Type Test. The flow is data-driven — each gem species has its own decision tree based on published diagnostic criteria.

GemID Phase 1 Origin determination for Malachite showing natural, synthetic, and imitation options with diagnostic tests

GemID Phase 2 Treatment detection for Malachite showing treatment types and diagnostic tests

Collections & Saving Hobbyist+

Save identification sessions to collections with notes, client information, and photos. Sessions sync across all your devices.

GemID My Collections screen showing a collection with edit and delete controls

What Gets Saved

All entered observations and measurements
Candidate results and conclusion
Stone name, specimen notes, and carat weight
Client name, examination purpose, and effective date
Purchase price, estimated value, and seller information Pro
Field photos and observation photos

GemID save dialog showing stone name, collection, dimensions, cut shape, carats, origin, treatment, and lab certificate fields

Organizing Collections

Create collections for each client, job, or lot. Rename, reorder, and delete from the Collections tab. Tap any saved session to reopen it in the identifier, continue adding measurements, or view the full record.

Reports & Export Pro

Generate professional examination reports from any saved session or batch of sessions. Reports include all recorded observations, candidate identities, and session metadata.

Report Builder

Select one or multiple stones from any collection
Choose output format: PDF, HTML, JSON, XML, or CSV
Toggle which sections appear: observations, candidates, next tests, notes, photos
Add a custom report title and job label
Download directly or send by email to a client

GemID generated identification report showing specimen name, observations, and candidate identities

GemID report builder showing format selection (PDF, HTML, JSON, XML, CSV), prepared-by field, generate button, and email option

Team Branding Team Pro

Team Pro workspaces can customize reports with your business identity:

Examiner name, title, and credentials on every report
Custom disclaimer and footer text
Default currency for valuation fields

Quick Report

From any saved session detail, tap Quick Report to instantly generate a single-stone PDF without opening the full report builder. Useful for fast turnaround on individual pieces.

Study & Practice

GemID includes a spaced-repetition study system designed around the property types tested in gemological certification exams (GIA GG, FGA, etc.). Learn to associate RI ranges, SG values, optic characters, and diagnostic features with specific gems through active recall.

Three Study Modes

SRS Review — spaced repetition scheduling based on the FSRS algorithm. Cards appear when they’re due based on your past performance. Optimizes long-term retention with minimal daily review time.
Free Practice — practice any cards at any time, no scheduling. Good for warming up before a lab session or reviewing a topic before an exam.
Exam Simulation — timed sessions with no hints. Silent mode auto-enables, hiding the answer until you commit your guess. Closest to real exam conditions.

GemID study mode selection showing SRS Review, Free Practice, and Exam Simulation

GemID study configuration showing session size, knowledge topics, and silent mode

Session Configuration

Filter by — all gems, gem family, color group, weak spots (cards you’ve gotten wrong), or a specific property type
Session size — 10, 20, 30, or 50 cards
Knowledge topics — mix in questions about instruments, gemological theory, inclusion types, and trade vocabulary alongside gem property flashcards
Silent mode — hides rationale and learning tips until after you answer

How Cards Work

Each card presents a question about a gem property (e.g., “What is the RI range of Tanzanite?”) with multiple choice answers. Tap “Tap to reveal answers” to see the choices, then select your answer. The card flips to show the correct answer with a detailed explanation of why.

GemID drill card showing a gem property question with Tap to reveal answers button

GemID drill card after answering, showing correct answer highlighted in green with detailed explanation

After answering, rate your confidence: Again (forgot), Hard, Good, or Easy. The SRS algorithm adjusts when you’ll see that card again based on your rating.

Progress Tracking

The study system tracks mastered cards, accuracy by property type, and streak data. Cards you consistently get right space out to longer intervals; cards you miss come back sooner.

For exam prep: Start with Free Practice to build familiarity, switch to SRS Review for daily retention, and use Exam Simulation in the week before your test. Filter by “weak spots” to focus on what you struggle with most.

Bulk Identification Pro

Process multiple stones in a single session. Designed for auction lots, estate parcels, and production runs where you need to identify many stones quickly.

Add stones with auto-generated lot numbers (Lot 001, Lot 002, etc.)
Quick-identify each stone with RI, SG, and color
Mark stones as “Identified” or “Needs Review”
Export the entire batch to CSV

Teams & Workspaces Team Pro

Team Pro lets your lab, shop, or classroom share identification sessions, apply branding to reports, and maintain an audit trail of who examined each stone.

GemID Team Pro screen showing shared sessions, branded reports, role-based access, and audit log

Features

Shared sessions — every team member sees the full gem record for every stone in the workspace
White-label reports — add your logo, examiner credentials, and custom disclaimer to all exported reports
Role-based access — Owner, Manager, Editor, and Viewer roles control who can create, edit, or just view sessions
Audit log — every session is timestamped with the examiner’s name; exportable for compliance
Invite by email — send invite links to add team members; they join your workspace on sign-up

Import & CSV Hobbyist+

Import existing gem data from CSV or JSON files into any collection. Useful for migrating data from spreadsheets, other software, or lab equipment that exports measurements.

CSV and JSON formats supported
Map columns to GemID fields (stone name, RI, SG, color, etc.)
Validation checks for out-of-range values before import
Duplicate detection based on stone name
Download a CSV template with all supported fields

Settings & Preferences

Access settings from the gear icon or the bottom navigation bar.

Show tips — toggle getting-started hints and the onboarding tour in the identifier
Expand all sections — open every test section by default instead of collapsing unused ones
Dark mode — switch between light and dark themes, or follow your system setting
Language — 15 languages: English, Spanish, French, German, Portuguese, Italian, Japanese, Chinese, Korean, Arabic, Russian, Hindi, Dutch, Turkish, Indonesian
Manage subscription — upgrade, downgrade, or cancel your plan
Delete account — permanently delete your account and all associated data