Gemology Fast Track / Unit 24 of 24 · Grading · 60 min

Reports, pricing and the final exam

Goal: Read lab reports, understand pricing drivers, then pass the final.

Labs and what their reports cover

Identification report

Species, variety, natural/synthetic, treatments. Every stone you sell as natural above a few hundred dollars.

Origin report

Country of origin opinion (Burma, Kashmir, Colombia...). Adds value for ruby, sapphire, emerald, Paraíba, spinel, alexandrite.

Grading report

Diamond 4Cs; some labs grade coloured stones (colour name like 'pigeon's blood' or 'royal blue' is a lab-specific trade term).

GIASSEF (Switzerland)Gübelin (Switzerland)AGL (USA)GRS (Thailand/Switzerland)Lotus Gemology (Bangkok)GIT (Thailand)AIGS (Bangkok)

Bangkok has several respected labs locally (GIT, Lotus, GRS, AIGS). For major ruby/sapphire sales, top-tier reports (SSEF, Gübelin, GRS, AGL, GIA, Lotus) are what buyers ask for.

Price drivers (relative, not numbers)

Colour quality
Size (price/ct jumps at 1, 2, 3, 5, 10 ct)
Treatment status
Clarity vs type
Origin (top stones)
Cut quality

Prices move with market and quality; build your own price notes from real offers in Bangkok/Chanthaburi and auction results, not from charts.

Final exam

Two parts. Pass mark 80%.

A · Written (40 questions)

Drawn from all units plus database-generated ID questions. Use the Final exam button below.

B · Practical (10 stones)

For 10 stones: RI, bire, OC, SG → ID → likely treatment → grade card. Use the ID Helper only to check after you commit an answer.

Practical
Do the Final exam. Re-study any unit where you score under 80% using its quiz and flashcards.
Unit quiz

0/4 answered

1. An origin report is most valuable for…
2. Which affects price most for coloured stones?
3. 'Pigeon's blood' on a report is…
4. Price per carat typically jumps at…
Unit 23Final exam