Master the Market. Source with Authority.
Transform your passion for gemstones into a professional advantage. Gain the insider expertise to evaluate and negotiate for gems with absolute confidence. Discover how much more there is to know about this exciting world.
This isn’t just a gemmology course. It is your entry pass into the inner circle of the jewellery trade.
Whether you are building a brand, advancing your career, or curating a personal legacy, the difference between an amateur and an expert is certainty. In an industry often clouded by opacity, misinformation, and cleverly disguised imitations and synthetics, knowledge is your most valuable asset.
Start your journey at the source of gemmology: learn about gemstone origins, see how gems are mined and how these extraordinarily valuable minerals get to market. Learn about gemmology quality and value factors for all types of gems, from Diamonds to Coloured Stones, Pearls, Phenomenal gems, and other Organics to Jade.
At JDMIS, we move beyond textbook theory. We train your eye and your business acumen simultaneously. You will not just "learn about gems" - you will learn to see them as seasoned dealers do. This comprehensive course gives you the knowledge and power to:
- For the Professional & Entrepreneur: Eliminate costly purchasing errors. Verify quality instantly, negotiate prices based on hard facts, and build a reputation for unshakeable integrity.
- For the Collector & Enthusiast: Stop guessing. Distinguish true rarity from marketing hype, discover undervalued treasures, and ensure every acquisition is a worthy investment.
Beyond the common trade practices, you will see imitations, synthetics and treatmented gems and understand the philosophy behind these whether used to harmlessly enhance or to deceive.
Preview video
Instructor's profile
-
Tanja Sadow
Tanja is an award winning jewellery designer & gemmologist with more than 4 decades of experience educating the jewellery industry across 4 continents. Dean and founder of JDMIS, Tanja works with aspiring artisans as well as top jewellery brand team members to help them achieve brilliance in their careers. Read More
- 1
Course outline
GT101 Coloured Gems - The Earth's Natural Wonders
Gain the strongest foundation for Coloured Gems
Navigate important facts from fiction: Discover the many varieties of beautiful natural minerals and how gemmologists classify them. See how easy it is to identify between different gem types. Understand the attributes of gems versus mere minerals.
GT102 Factors Affecting the Value of Coloured Gems
Command the Coloured Gem Market
Discern Value Instantly: Move past basic identification to discoved that, unlike diamonds, the 4 C's are weighted differently when applied to coloured gems. Learn to evaluate the subtle nuances of colour, discover how clarity types are assessed and see how cut can affect market price. Start to learn how to make use of practical jewellers tools of the trade.
GT103 Natural Diamonds, Simulants & Synthetics
The Diamond Authority
De-Risk Your Investments: The origins and history of diamonds are reviewed to reveal ture rarity of this unique Gem. Many materials are made to resemble diamonds; some can be easily identified, while others nearly identical. Master the differences between natural, synthetic (lab-grown), and simulant diamonds. Spot the "too good to be true" deals before they cost you.
GT104 Diamonds, the 4 C's & Beyond
Go beyond the 4C's.
Audit Quality Factors: Learn the trade-specific evaluation techniques that determine a diamond's worth. Find important compromise in the evaluation process which can save you 1000's of dollars and discover where compromise is not acceptable.
GT105 Pearls: Natural, Cultured & Imitation
The Pearl Expert
Appreciate Rare Organics: Discover the true origins of saltwater vs freshwater Pearls, the rarity of Natural compaired with cultured and the difficulties and limitations Pearl farmers currently endure. With imitations existing for centuries, find how challenging it can be to distinguish these and newer imitations with todays technology.
GT106 Assessing Pearl Value
Buying with Confidence
Curate with Precision: Understand how to assess the critical factors—colour, lustre, shape, surface characteristics, nacre thickness, and make - that separate commercial goods from heirloom quality. Learn about two special collector quality Pearls which are super rare. How to care for all Pearls is closely addressed.
GT107 Phenomenal Gemstones
Master of Phenomena
Identify Rare Effects: Develop the eye to spot "Phenomenal Gems"—those displaying Asterism, Chatoyancy, Aventurescence, Irridescence, Play of colour and Colour-change properties—adding the knowledge to aquire exotic, high-value pieces to your portfolio. In one session discover an array of these special gem materials which react in amazing ways to certain light sources. See a wide range from common varieties to the most rare and expensive of collectors’ items in natural, synthetic and imitations all handled and viewed closely.
GT108 Jade and Jade Imitations
Demystifying Jade
Decode the Jade Market: As one of the most popular gems in the Far East, Jade has many imitations, and only two recognised forms. Uncover the complex world of Jadeite and Nephrite from history and lore to present day value factors and selection process. Understand the true meaning of A, B, and C jade (natural vs treated) to protect yourself in one of the world’s most high-stakes markets. Observe and view first-hand the many imitations available on the market today and see some of the difficulties which arise in mining Jade.
GT109 Organic Gems
The Unsung Heros
Appreciate Rare Organics: Gain specialized knowledge in Amber, Coral, Jet, Ivory, Bone, Shell and other lesser known materials opening new avenues for vintage dealing or niche design. Although worn throughout history they are less appreciated in Asia than the more popular gems previously covered. (This topic is Video-only and not a hands-on classroom segment.)
GT110 Imitations, Synthetics, Assembled gems, Summary, Testing & Next Steps
Strategic Buying & Testing
Future-Proof Your Skills: Get hands-on ppractice viewing Imitations, Synthetics and Assembled gems. Practical testing methods are discussed highlighting the importance and role of laboratories. The available testing equipment and gemmological techniques are highlighted together with the important topic of treatments and enhancements, ensuring your knowledge stays ahead of evolving industry developments.Student reviews
-
Fantastic course! Hands on material to practice with. Help me in future buying of gemstones and jewellery.
- Poh Lin K. (Singapore)
-
Awesome class as always! I have more knowledge about gemstones that I can buy and incorporate into my jewellery designs.
- Arathy S. (India)
-
Great video training! I have retained learning most from the video with Tanja. Many thanks!
- Lee Kim G. (Singapore)
-
I really liked how the video materials can be seen , touched and observed during the practical sessions in class. The class size was also kept in a small group so that we could have more time to interact with our instructor.
- Jia Min L. (Singapore)
-
A great place to understand gems. It is really practical and useful... I would like to apply what I have learnt in buying the gems/ jadite or pearls when the occasion arises.
- Davi B. (Singapore)
-
Excellent course!!! Highly recommended...Very well prepared and paced
- Yiming L. (Singapore)
-
Good knowledge and hands on. Great instructor who has a vast knowledge of the gems and industry. I have become more knowledgeable, less skeptical to scams to buying gems and increased basic knowledge to mining, gems and the environment.
- Jasmine L. (Singapore)
-
The material is well-written. Very informative. The trainer is a subject matter expert and imparts a lot of knowledge to us. The training administration is seamless and makes the registration process very smooth. Staff is friendly and prompt. (I will use the skills) to start a business & buy gems with more knowledge.
- Moy Yin L. (Singapore)
-
Perfect class size. Love the face to face lessons, the physical examples for reference and learning, and the interactive lessons. The online lessons were well organised too! The videos were clear and well paced. The online notes and physical notes were very helpful too! I like the fact that we can always log back onto the learning platform to recap moving forward. Thank you to our trainer, Tanja too! Very engaging, clear communication, knowledgeable!
- Pauline S. (Singapore)
-
The course is great, even for beginnners. Very very informative and makes us understand very well with lots of examples. Only small improvement will be for the instructor to take note of the time of the physical class as sometimes the class can overrun, especially when students start to ask a lot of questions.
- Kai Xuan Y. (Singapore)
-
A very good learning experience. Lots of practical application. Great instructor who is very experienced and able to communicate concepts effectively.
- Su Ean H. (Singapore)
-
Fantastic and very professional. Small class size and great teacher. They cover a lot of things and the online courses were easy to grasp and fun. The assessment was necessarily difficult and very helpful for remembering. One of the best courses I have taken.
- Fuling S. (Singapore)
-
It has been an incredibly rewarding experience to be part of this class. The training materials are very comprehensive and the effort that has gone into producing them deserves a huge compliment. Being able to touch, feel and assess the gems in class with classmates has made the lessons truly come to life. Tanja deserves nothing less than the utmost compliments I can give to a trainer, hands down the best trainer I’ve encountered in any SkillsFuture course to date.
- Pamela P. (Singapore)
-
It is an excellent course to attend for those who enjoy gemstones, diamonds, jade as well as phenomenal gems. It can be very useful in buying gemstones and how to read and understand gem and diamond certificates.
- Julia N. (Singapore)
-
Informative course! Please attend if you have keen interest in gems and diamonds! I collect crystals and make bracelets so going through this course helps me in my purchase of the materials!
- Cindy W. (Singapore)
-
I'm thinking of going into jewellery business. So this gives me a good foundation, especially in buying jewellery. Interesting stories shared (by the instructor) will give you better understanding and what to look out for when you buy a piece of jewellery.
- Ericka T. (Singapore)
-
This is such a Great course with very solid content knowledge to be acquired! I can talk to my husband about the gems and Jade now as he is a huge fan of these gemstones.
- Panpan G. (Singapore)
-
It was a wonderful course and I have learned a lot, this is definitely a good start to the world of gemology. My family members are avid gem collectors and the knowledge I gained would come in handy during our gem hunt.
- Ee K. (Singapore)
-
This will be useful for my e-commerce store.
- Fannie T. (Singapore)
-
I only wish we had more time to look, see and feel more samples of the gems. Otherwise I thoroughly enjoyed myself. It gives me an impetus to learn more about this industry and what it has to offer.
- Claudia G. (Singapore)
-
Highly recommended! It's good to have time set aside in the week to properly digest the videos. It contains the broadest scope of coverage - appropriate given the current consumer interest.
- Joanne O. (Singapore)
-
I definitely like this training with good and useful knowledge learnt. It will be good if we have more time to practice during the class... Thank you very much for the training and SkillFuture claimable is also an helpful factor. Thank you.
- Emily P. (Singapore)
-
As a gem dealer, this (course) was brilliant.
- Mohamed N. (Singapore)
-
JDMIS is truly awesome. Worth any time and money you invested in. Regardless of whether you are in the jewellery trade or not this is good knowledge.
- Imran A. (Singapore)
-
I love the way Tanja teach! The class were never bored as she fills the lessons with examples and stories related to the topic of the lessons.
- Louis L.(Singapore)
-
Love the history, story and trade sharing by Tanja... Very insightful learning!
- Eileen L. (Singapore)
-
Loving the gem course and Tanja is always very informative... It's engaging and full of new information
- Faizal S. (Singapore)
-
The curriculum is more than what I expected. I felt engaged throughout the 5 days of lessons. Tanja brought so much industry experience to share. I would recommend this course to all gemstone lovers and those who appreciate the beauty of nature.
- Eva W. (Singapore)
-
Tanja is amazing, professional and really experiece and patient with all of us.
- Scott P. (Singapore)
-
Great instructor, great course materials and fun environment... I really learn a lot from this course and really love it. I can identify my gemstones better.
- Su Myat T.
- GT100 quote 34
- GT100 quote 33
- GT100 quote 32 - blended
- GT100 quote 31
- GT100 quote 30
- GT100 quote 29
- GT100 quote 28
- GT100 quote 27
- GT100 quote 26 - blended
- GT100 quote 25
- GT100 quote 24
- GT100 quote 23 - blended learning
- GT100 quote 22
- GT100 quote 21
- GT100 quote 20
- GT100 quote 19
- GT100 quote 18
- GT100 quote 17
- GT100 quote 16
- GT100 quote 15
- GT100 quote 14 - blended learning
- GT100 quote 13
- GT100 quote 12
- GT100 quote 11 - School general
- GT100 quote 10 - trainer
- GT100 quote 9 - trainer
- GT100 quote 8
- GT100 quote 7
- GT100 quote 6 - trainer
- GT100 quote 5 environment and instructor
Duration & Training Modes
Duration: 3-5 weeks
Mode: Blended or E-Learning
All important theory and practical demonstrations will now be delivered through asynchronous (self-paced) online learning. This means that students go through most of the learning at their own pace and convenience via a comprehensive series of online videos and attend live interaction sessions (physical or online) afterwards to receive maximum support and guidance under expert instructors to reinforce the learning of key skills and concepts. For more information on different training modes, click here .
JDMIS also has flexible make-up schedules and graduates can return for free for refresher courses (subjected to availability).
-
Learning path
This course is a Core Component of all learning paths. We refer to these modules as CC.
Next Step: GT200 - Jewellery Trade Practices 2: Gem Identification Methods.
Next Step (Complementary Jeweller's Knowledge):
FT100 - Jewellery Fashion Trends 1: Epic and Contemporary Trends.Participants attending and completing this programme as a stand-alone certification can choose to enroll for any full diploma.
-
Facilities
The live classes (of the Blending Learning mode) take place in our Gem Vault where participants are able to see, examine, scope and understand Tanja's collection of over 1,800 gems, jewellery pieces and examples, including rare and valuable specimens as well as common imitations found in jewellery markets in the region.
-
Tools & Materials
Blended-learning students will receive everything they need to complete all their coursework. The course fee includes all the tools, drawing materials and reference materials required for students to complete their coursework efficiently.
e-Learning students may opt to purchase the standard JDMIS toolkit from us or procure the necessary items themselves.
- 1
Course Fee:
Invest in Your Creative Future
One payment. Lifetime access. No recurring fees.
Private Atelier Experience
30 hours exclusive in-studio training with Master Trainers
Available for corporate groups & private cohorts (min. 6 participants)
Self-Paced Essentials
Learn at your own pace
Guided Certification
Get certified with expert feedback
Classroom Immersive
Global Live Interactive
Maximum transformation
Add the Professional Toolkit
Everything you need to complete every project
Why Lifetime Access Changes Everything
See how different learning models compare
Monthly Subscriptions
Pay monthly to access. Stop paying = lose everything. Want to revisit in 2 years? Subscribe again.
Traditional Schools
Show up, hope you learn, go home. No recordings, no second chances. Miss a class? Miss it forever.
JDMIS Lifetime Access
Pay once, own forever. Revisit any module, any time, for life. Your content never expires.
Course Gallery
Frequently asked questions
-
What is the difference between the different Modes of Study +
The JDMIS Private Atelier Experience is most like a traditional workshop experience. Everything you do is in-person, in Singapore's most comprehensive jewellery training facility, with the support of a jewellery expert. There are readings and practice you can and should do at home, but your instructor is with you to deliver every piece of imporant information and support your learning throughout the learning activities and/or projects.
The JDMIS Classroom Immersive Experience less intense that the Atelier Experience. It provides the very best value balance between the full Atelier Experience and managing your training by yourself. All the relevant course content you will need to learn and refer to in the future is included online via the JDMIS learning management system. You have segments of the course you will be expected to review before each in-person experience session. When you come into class, your instructor will work with you to reinforce your learning with examples and projects that enhance your online learning. This option is generally considered to be the most desirable form of training for anyone who is based in Singapore or can visit Singapore.
The Self-paced Essentials is the exact opposite of the Private Atelier Experience. All the the same information - but completely self-paced. It is completely up to you to plan time to review and understand the course content, work on the learning activities and/or projects, and complete all of the requirements of the course. Nobody will chase you if you dont have time and need to postpone your progress, and you can always pick up again where you left off, or start again whenever you like. This option does not have any time limits, does not put any pressure on you to complete assignments, has no tests and does not include any validation of your work.
If you are thinking you would like to have a qualification to show your achievement, this requires that you connect with our expert team of trainers and have them review your work to validate your skill, and for you to complete a final examination to validate your knowledge and understanding. This is where the Guided Certification option adds value. It unlocks the project submission elements in the curriculum and JDMIS expert instructors will review and feedback on your work - providing valuable information on your progress and areas of improvement. You will also be able to complete a final examination online that, together with course submissions, registers your qualification in the JDMIS Professional Qualification Register, allowing you to share your achievement as a verifiable online certificate of website slider or badge.
The JDMIS Global Live Interactive option provides more support that the Guided Certification option via remote live learning sessions specifically for small groups of participants abroad, or unable to complete physical training sessions in Singapore. These training modes represent the highest level of support available to JDMIS global audience.
-
How will the schedules work? +
Online portions of your jewellery training will be delivered through exceptionally produced high-definition videon presentations, packaged in a micro-learning format, that you can view at your own pace and convenience.
Participants Private Atelier or Classroom Immersive training options will choose specific scheduled to follow as part of the admissions process. If you need to miss a session, please inform our registrar in advance so that they can coordinate a make-ul lesson for you.
For online live sessions such as Global Live Interactive lessons, weekly group office hours, and 1:1 assessment/review sessions, options are provided in multible time-zones to facilitate access to individuals with diverse work or family commitments.
-
What if I have questions during self-study? +
The learners from all live courses (Private Atelier, Classroom Immersive and Global Live Interactive) will receive access to an exclusive WhatsApp Group where you can get feedback from instructors and engage in discussions with your fellow students. This is an immediate channel where questions normally are attended during working hours by instructors, JDMIS team membbers or even fellow participants in your course.
Participants in the Guided Certification options can post questions to the community forum, in which JDMIS instructors and other participant are present and interact, but with lower frequency. Guided Certification participants also have access to weekly 'office hours' a 30-60 minute group session where course participants and graduates can join in to ask questions on a first-come-first-served basis within the scheduled session. You can also use your two 1:1 discussion sessions to review any questions you may have.
Self-study participants only have access to community channels. They may however upgrade at any time to other more comprehensive learning options.
-
How much time do I need to study a week? +
If you choose a self-paced course option, you conduct your study at your own pace that suits your learning style!
Guided certification options allow you to complete your validation steps within 6 months - allowing you to plan your training at your own pace.
For live sessions (in Singapore or abroad) you should plan for each course to involve at least 15 hours of online asynchronous commitment (self paced) 6 to 15 hours of scheduled live sessions, and approximately 10-20 hours of additional own-time practice.
-
Are the tools & materials included? +
The cost of tools and materials is already included in the course fee of Private Atelier and Classroom Immersive options. All participants in these sessions will receive the same tool kit ensuring they can complete their course efficiently.
Participants joining any of our other online learing options are eligible purchase the same toolkit by letting our registrar know at the time of your registration. Shipping costs apply both to local and international tool and material purchases. We can advice on these as part of the admissions process.
-
How will my assignment be graded and what do I need to pass? +
You are responsible for completing the online lessons before attending the live sessions with JDMIS instructors. If you are completing any certifiable variant of our courses, that course will have several milestone assignments which you need to complete and submit by specified deadlines in order for your instructors to review and provide feedback.
In order for your instructors to review your assignments and provide feedback, you need to take photos/scans of your completed work (design or jewellery piece) and submit them onto the JDMIS online assessment portal.
You need to obtain an average mark of 60% or higher to pass the course and receive your Certificate of Completion.
- 1
Free refresher classes, access to retail space and industry events!
