It was all online. I just sat down, took notes as I went along, took the test at the end, and was done! It's largely aimed at sales, but I liked learning more about things I'm not as familiar with (colored stones, for example).
Back in the mid to late 80s, I took the Gemologist program from the GIA via their Distance Education department.
It consisted of 5 classes:
1-Diamonds
2-Diamond Grading where they mailed stones for you to plot and grade
3-Colored Stones
4-Colored Stone Grading
5-Gem Identification with a 20-stone final challenge, misidentify just one, and you fail (you get 3 tries). Needed instruments e.g. refractometer, dichroscope, loupe, specific gravity fluids, polariscope, etc. To test unknown specimens.
This class took me a long time to get through.
The other 4 courses had proctored final exams, then a proctored comprehensive final exam covering all 5 courses.
So I am a Gemologist (GIA) 1989.
To get my GG, I would need to go back and complete the 3 lab courses.
I took these classes for fun because I was always interested in gems, and wanted to learn more, no PS back then.
Subscribed to JCK and National Jeweler for awhile but never worked in the industry because there was more money in Software Engineering (retired as a VP in 2010).
I complete the certificate in gemmologist online from Gem-A (the British version of GIA) in 2012. I had intended to carry on and complete the diploma but my marriage broke up that year and I went through alot of trauma leading up to doing my exam and didn't really have it in me to get up and do it all again.
I also realised through doing it that I prefer the retail/customer relations side of it and handling jewellery rather than the gem testing side.