I am a G.G. and F.G.G. I signed up for the I.S.G. as kind of a
refresher because so many things have changed in the field of
gemology since I got my degrees in the mid 80's.
I am completely impressed with the quality and quantity of
available through the International School of Gemology.
It is constantly being updated and improved. A real cutting edge
tool...all for a price that is comparable to a magazine
subscription! The site was written by a graduate of the British
Gemmological Association and the Gemological Institute of America.
The forums on the sight are great; really helpful as well.
I totally recommend ISG!