How to Become a Gemmologist

We sometimes get asked how to learn about diamonds and the jewellery business; where does one learn about diamonds, and pick up the formal training in the study of them? The diamond business is largely private, for understandable reasons. Most shops are family businesses, so on-the-job training is hard to come by.

Some well-worn training manuals!

The gold standard qualification in the diamond business is the GIA’s Graduate Gemmologist (GG) program. The Gemological Institute of America is the foremost authority on diamonds and gemstones in the world, a not-for-profit who invented much of the terminology we use every day to describe diamonds, and whose laboratory is at the cutting edge of diamond research. It is their highest qualification, and teaches you everything that needs to be known about precious gemstones. This can be studied either on-campus, which takes about six months, or by distance education, where the course books are mailed to you (today a lot of it can be studied online, but I always feel that there’s nothing like a physical book!) and proctored exams are mailed back to the GIA for grading. (I think the exams are online now too!). The exams are taken at the end of every section, and the theoretical learning goes hand-in-hand with real hands-on experience, where you travel to one of the GIA’s campuses for a week-long training class. This is the pathway I took to my GG.

Accredited Jewellery Professional (AJP)

This is the GIA’s starting qualification, which gives a broad grounding in the diamond and gemstones world. You learn about the four C’s (colour, cut, clarity and carat), as well as gaining a basic introduction to emeralds, sapphires and rubies. This section of the course is quite quick, most people I spoke to finished it in a couple of months. gia microscope

Diamond Graduate (DG)

The next step is the diamond graduate diploma – this is where the real work begins! Over twenty modules, you learn in an in-depth manner all about diamonds, how to grade and assess them, learn about diamond simulants & synthetics and how to detect them, and also drill down even further in colour, clarity, cut grading and carats. The course takes you through the geology of diamond formation, the evolution of diamond cutting, the diamond crystal and how light interacts with it, repairing and recutting diamonds, and the nuances and finer points of colour and clarity grading. At the end of the course, you travel to the GIA campus (I went to London, but New York is another option!) for a week’s practical instruction. This is where the GIA comes into its own – the quality of instructors they have is second to none, and they have an extraordinary collection of practice diamonds to look at and train with – there is a diamond with every type of inclusion, for example, or every cut variation, so that you will never come across something new in the real world. At the end of the week you have to pass an exam where you grade two diamonds to GIA standards. What is particularly hard is plotting clarity onto a cert, and learning all of the different factors to consider in a cut quality grading.

Graduate Coloured Stones Program

Having mastered diamonds, the next part of the course looks at all of the other gemstones; there is a strong focus on the “Big 3” of emeralds, sapphires and rubies, although the course covers all of the main other gemstones likely to cross your path, such as amethyst, opal, tanzanite, garnet, and also a few that are less common, such as feldspar, spodumene and diopside. Each stone is broken down into quality and value factors (what to look for and what to avoid), the world market, the main sources, mining, treatments and enhancements, and key concepts and terms. At the end of this section, there is another practical session in the lab, where you learn how to use lab equipment to identify different stones. The course material spans two large folders, and is unbelievably thorough.

Gem Identification

Hand-in-glove with diamond grading and coloured stones is the Gem Identification module, probably the most difficult of them all! This module is all about learning the nuts and bolts of laboratory work, learning how to use the most commonly needed instruments such as a refractometer, dichroscope, spectroscope, and specific gravity scales. Real world scenarios are taught, such as where to start when given an unknown gemstone. You also learn how to distinguish between two similar stones, and which tests are needed in any scenario.

As is usual, this course is followed by another week in the lab, with a lot of practice at identifying unknown gemstones. All of this is leading up to the final end exam, the twenty stone challenge!20160202_154313

Twenty Stone Challenge

This is the final exam you have to take, and given the importance of it, it is a really difficult one! You are given twenty stones, and have to identify them in six hours. The only catch is that the pass mark required is 100%! You will need almost all of the time to finish, and it is certainly the toughest exam I have ever sat!

One thing that was very interesting about the course was the range of people studying it; there were students from every continent, different ages, and working at all ends of the business. Two students were working for a well-known TV shopping channel, one was working for probably the most prestigious jewellers in the world, one ran a small chain of shops in Europe. The qualification was necessary no matter what end you were in, and was going to further the career of each and every one of them. To find out more about the GG diploma, and about GIA’s London campus, see

The goal! A Graduate Gemmologist Diploma!