Invest in yourself.
Accelerate your path towards a gemology career.
Enroll in our Professional Gemologist certification course and learn new skills.
Learn basic gemology. Understand gem properties. Use gemology tools. Identify gemstones.
Serving gemology students since 1998
The International Gem Society (IGS) was the first Internet-based school of gemology to serve a global audience. Our goal is to provide an affordable education in gemology.
IGS’s founder — Donald Clark, CSM IMG — created a robust testing process to ensure that those with IGS certification would stand out in the crowd. IGS continues to use the testing process created by Donald Clark to ensure continuity and rigor.
What Our Students Say About Us
“What started as a hobby is now a small home business for my wife and I”
“I have never known or heard of an organization that offers so much for its members, and at such a low cost. What started as a hobby in 1998 and now is a small home business for my wife and I has been made so much easier by the information you supply. Thank you.”
Ernest and Peggy Roisch
Rainbow Rocks, LTD
“What a gift you give, passing this knowledge to those of us who are seekers”
“Just wanted to thank you for the fantastic adventure I have had since becoming a member of IGS. The quality of your Gemology Course is tops. Nice to know that such folks as you exist. What a gift you give, passing this knowledge along to those of us who are seekers.”
Dr. John Parrott
IGS Pro Member
“It’s like a good who-done-it mystery. It just can’t be “put down.”
“You are one heck-of-a-writer. This course is so well written, that I’m convinced that anyone, even me, can understand and master this material. After having read the first four introductory articles, I find myself actually wanting more time to study. It’s like a good who-done-it mystery. It just can’t be “put down.”
IGS Pro Member
“It doesn’t matter how much you think you about gems, you never stop learning”
“You know the best thing that I’ve learned from your great course is that it doesn’t matter how much you think you about gems, you never stop learning. Each day there is something more to learn, and it will never stop. Thank you for all the help, education and support that you give IGS members.”
IGS Pro Member
Certification Course Modules
All the information you need is located on our website in our Learning Center. There are no other books required. The gemology course is divided into sections and follows our Syllabus. We also have a list of recommended gemology tools.
An Introduction to Gemology
Our introductory module covers basic gemology concepts and terminology. It forms the foundation for the entire course.
The Advanced Gemology module introduces the more complex subjects, such as the optical and physical properties of gemstones.
Here we teach you how to use the tools of gemology and what to do with the information they supply. This is the essence of gem identification.
This section details the factors used in grading diamonds and colored stones.
Advanced Gem Information
Here we take your basic understanding of gems and dive deeper into the details of specific gems, such as corundum, spinel and garnet.
Once you have learned how gems differ from one another, how to identify them and what properties determine their value, you can begin to develop your appraisal skills.
Are you ready to invest in your passion for gemstones?
Make this the year you take the leap.
Some questions we often hear
Will I be assigned an instructor for the course?
The benefit of this approach is that each student can learn at his or her own pace, and on his or her own schedule. Students can take as long as they want to complete each exam in the certification process to ensure familiarity and understanding of the material.
Won’t the self-study model be difficult if I’m a beginner?
For beginners we recommend following our structured Syllabus, however you may study the material in any order that suits you.
What is required to pass?
In order to pass the certification process the student must:
- Pass three 100-question written exams with a score of 87% or better. The student may retake the exams an unlimited number of times until they pass each one.
- Thereafter, the student must also pass a practical exam which requires identifying and grading 15 gemstones. We will mail you the gemstones, which will be common to the trade and include natural, enhanced, synthetic, and assembled stones. Deductions will be made for errors, and the applicant must score 87% or better to pass.
- When the written and practical tests have been completed with passing scores, the IGS-Certified Professional Gemologist certificate will be awarded.
How is the material administered?
All examinations are administered via online test-taking software accessed via your password-protected account on the IGS website.
Can I see a sample of the test questions?
Sure! We’ve posted the following sample gemology questions from the actual IGS certification exam. This should give you a sense of the scope of the tests. Questions cover gemstone formation, properties of specific gems, gem identification, and testing, as well as faceting, grading, and appraising.
How long do I have to take the exam?
As long as you remain a member, you can take the written exams (and the practical exam) whenever you feel ready. You may repeat the written exams if you fail.
How long should it take me to complete the course?
The course is quite involved. This is not a casually created e-course, but rather a very comprehensive overview of some challenging material. We’ve been improving the material for over 20 years. Some members with previous gemology or geology experience have completed the course in as little as three months, others are still chipping away at it after two years. It really depends on your level of interest, motivation, and time commitment. The average time to completion is probably around a year, studying part-time.
Can I get a refund if I am not satisfied?
Please note that certification costs are non-refundable. A $50 refund is given if you choose to return the stones used for the practical test. (You may keep the stones instead, if you wish.)
How does the IGS course compare with those offered by the GIA or similar organizations?
The GIA is an excellent organization. Their Graduate Gemologist degree is the most respected credential a person can hold in this industry. If you have the time and money, and are serious about a career in the gem industry, the GG course of study offered by the GIA should be your first choice.
The IGS certification program was created for everyone else. The founder of IGS and original author of the program, Donald Clark, has strong connections with the lapidary community. For years, he listened to amateurs giving inaccurate advice to others. For example, he heard things like: “If your blue stone has an RI of 1.625, then it is topaz, not aquamarine.” Those two properties, color and RI, also belong to tourmaline and a few rare minerals. Blue topaz and blue tourmaline have vastly different values. Not knowing the difference can be costly, in terms of both money and reputation.
Donald Clark believed that the problem stemmed not from the well-meaning lapidary sharing his incomplete knowledge, but rather that there wasn’t anywhere to learn gem identification, short of taking (what was back then) a $3,000 course. For them, he created IGS. It is dedicated to all the gem cutters, collectors, jewelers, and others wanting to know more about gems. The Professional Gemologist program was also created for those lacking the resources for a GG degree. A typical example would be a person making a midlife career change. This often involves working two jobs for a period, or the time consuming process of starting a new business.
What the certification tells a customer, or potential employer, is that the holder has proven their knowledge of gemology: that they are well versed in its terminology, the properties of gems, how they are valued, and that they possess the skills and knowledge to distinguish one gem from another. But let us be clear: having the IGS certification may open doors to a career in gemology. But it is the way an individual presents themselves and his or her actual experience and work ethic that determines success.