Gubelin Gemmology

The Gübelin Gem Lab and GIA (GIA Education) are delighted to release a joint statement to confirm that Ethiopia is a new source for copper-bearing (paraiba) tourmaline.

Following the rigorous analysis of several hundred reference stones acquired from reliable sources in Ethiopia, the Gübelin Gem Lab has established robust criteria to distinguish Ethiopian material from other known origins. A comprehensive publication in a gemmological journal will be available to read in the coming months.

The Gübelin Gem Lab will now issue Ethiopia as an origin on our reports for any paraiba tourmaline that meets described criteria.

GIA and Gübelin Gem Lab Confirm New Source of Copper-Bearing Tourmaline from Ethiopia - Gübelin Gem Lab For the duration of the fair, the Gübelin Gem Lab (GGL) will offer express on-site testing service for all major gemstones with no express charge.

The Gübelin Gem Lab will provide express on-site testing services for all major gemstones free of express charges at the 74th Bangkok Gems & Jewelry Fair.

Date: 8–12 September 2026

Opening hours: 10:00 a.m. – 6:00 p.m.
(Note: The cut-off time for submitting items at the booth on 11 September is 2:00 p.m. This may be subject to adjustment depending on circumstances.)

Location: Booth No. FD005, Queen Sirikit Convention Center

Booth contact numbers: +66 98 257 1049 or +852
9317 2056

You are welcome to submit your gemstones to benefit from our express testing services. Items submitted by 2:00 p.m. at our booth or 4:00 p.m. at our office (45/1, Soi Silom 19, Silom Road, Silom Sub-district, Bangrak District, Bangkok 10500, Thailand) may be collected in the afternoon two days later.

From 7–11 September, we will also accept goods directly at our Gem Lab (address above) until 4:00 p.m. on 11 September. (Note: This may be adjusted depending on the circumstances.)

Office hours: 9:00 a.m. – 5:00 p.m.
Express service ends on 11 September. Orders submitted on or after 12 September will follow regular testing times.

Please book an appointment in advance by email at [email protected] or call:
Local phone: +66 2 267 5442
Local mobile: +66 98 257 1049

Join Gübelin Academy`s upcoming courses this fall 2026 and be inspired by the incredible world of coloured gemstones.

Next Courses
Lucerne, Switzerland (English)
10-11 September Level 1
14-18 September Level 2
21-25 September Level 3
28-29 September Practice Days
29-30 October Level 1
2-6 November Level 2
9-13 November Level 3
16-17 November Practice Days

Hong Kong (Mandarin)
10-11 September Level 1
21-25 September Level 2 - fully booked
29-30 September Level 1
5-9 October Level 3
21-22 October Level 1
26-30 October Level 2

Register at: [email protected]
Gübelin Academy courses also in Hong Kong (Mandarin)

Pearl grading is the process of evaluating a pearl's quality based on a number of characteristics. One of these characteristics is colour.
Pearls occur in a remarkable range of colours. When evaluating pearl colour, Gübelin gemmologists refer to the pearl's body colour and overtones.
The body colour is the pearl's dominant or primary colour. Body colours can range from white, cream, silver, black, and gold to shades of pink, green, blue, brown, and many others.
The overtone is a subtle secondary or modifying colour. Common overtones include pink, green, blue, and purple.
Want to learn more about the beautiful effects light can create in gemstones? Enrol now in our courses and explore the science behind their natural beauty. New dates now open for Fall 2026. Contact us to book your place: [email protected]

10-11 September Level 1 (English) Switzerland
14-18 September Level 2 (English) Switzerland
21-25 September Level 3 (English) Switzerland

29-30 October Level 1 (English) Switzerland
2-6 November Level 2 (English) Switzerland
9-13 November Level 3 (English) Switzerland

Gem aficionados can deepen their knowledge anytime, anywhere with the Gübelin Academy's online course, Coloured Gem Professional: The Basics. Designed for enthusiasts, collectors, jewellery professionals, and connoisseurs, this self-paced course introduces the historical, cultural, and gemmological foundations of the "Big Three"—emerald, ruby, and sapphire—while exploring their beauty, significance, and scientific characteristics. No prior knowledge is required, and each of the four modules can be completed individually. The course fee is CHF 236 (USD 265) and provides the foundation for progressing to Coloured Gem Professional Level 2.
Click the link below to register and begin your journey into the fascinating world of coloured gemstones.

NEXT GEMSTONE TESTING SERVICE WITH CGG IN SHANGHAI, CHINA

We are pleased to announce our upcoming Gemstone Testing Service with CGG in Shanghai, China, and warmly invite you to take advantage of this convenient opportunity to access our services locally.

We will offer free express on-site testing services for all major gemstones at no additional charge.

Event Details
Dates: 12 - 21 August 2026
Opening Hours: 10:00 a.m. - 5:00 p.m.

The event will be conducted in two sessions:
Session 1: Consultation Services

12 - 14 August 2026
During these three days, our gemologists will provide verbal consultations regarding gemstone potential colour or treatment.

Session 2: On-Site Testing Services
17 - 21 August 2026
Comprehensive on-site testing services for all major gemstones will be available throughout this session. Testing will be conducted on-site, and test results will be provided during the event period. Official reports will be issued within 1 to 2 weeks thereafter.

Location:
1st Floor, No. 99 East Beijing Road
Yifeng Galleria
Shanghai 200002, China

Local Mobile: +852 9386 1787
For organizational purposes, we kindly ask that you contact us in advance to arrange an appointment:
Tel: +852 2868 2781
Email: [email protected]

We would also appreciate receiving an estimate of the number of stones you intend to submit for testing.
Should you have any questions, please do not hesitate to contact us.
We look forward to welcoming you and meeting you in Shanghai.

What if smaller gem labs could access the analytical power of one of the world’s leading gemmological institutions?
Gemtelligence™ was created to help laboratories overcome a fundamental industry challenge:
the lack of large-scale “Ground Truth” reference data required for accurate and consistent gemstone interpretation.
Now, Gübelin Gem Lab offers Gemtelligence™ as a Software-as-a-Service platform for external laboratories and jewellery brands.
💎 AI-supported origin and treatment determination
💎 Trained on years of curated gemstone data
💎 Compatible with standard analytical instrumentation
💎 Designed to improve consistency and efficiency
This is not about replacing gemmologists. It is about giving laboratories new tools to navigate an increasingly complex gemstone market.
We are excited to help shape the next chapter of gemmology.

As we head into August, we're celebrating its beautiful birthstone, the peridot.
Peridot is an idiochromatic gemstone, meaning its vibrant green colour is an inherent part of its chemical composition rather than the result of trace impurities. Every peridot owes its distinctive colour to iron within the crystal itself.
Many recognise peridot by its characteristic oily lustre, its strong double refraction, and its distinctive 'lily pad' inclusions, as seen here under magnification.
Would you like to understand why gemstones have the colours they do? Or learn more about concepts such as lustre, double refraction, and the optical properties that make each gemstone unique?
Our Level 2 course explores these topics in greater depth, helping you build the knowledge and skills to confidently identify and understand gemstones.
And before you go, here's a question for you...
Which crystal system does peridot belong to?
A. Hexagonal
B. Trigonal
C. Orthorhombic
Answer: C. Orthorhombic
Did you get it right?

Level 2 (English) Lucerne Switzerland 14-18 September 2026
Level 2 (English) Lucerne Switzerland 2-6 November 2026

To book your seat get in touch with us at: [email protected]

Layered Structure
Growth structures are among the most common internal features observed in gemstones. Solid inclusions frequently align along these growth planes, recording the crystal's formation history. This photomicrograph shows fine dust-like particles arranged in distinct geometric, parallel layers, beautifully outlining the sapphire's growth structure.
The inclusion scene was documented in an unheated sapphire weighing over 100 ct from Sri Lanka.
Photomicrograph: Klaus Schollenbruch, Gübelin Gem Lab, Lucerne
Photo: Alisa Milakova, Gübelin Gem Lab, Lucerne

Mikado
Several rod-shaped amphibole crystals were found in a 3.6 ct emerald from Zambia’s Kafubu area. Crossed polarizing filters reveal vivid, iridescent colours within the inclusion scene.
80× magnification, 20 images stacked.
Photomicrograph: Klaus Schollenbruch, Gübelin Gem Lab, Lucerne
Photo: Alisa Milakova, Gübelin Gem Lab, Lucerne