The book gave excellant background information on the subject.
I was not looking for background, so it was not helpful to me. I believe it would be very good for someone interested in the technical aspects of the subject.
This book is just full of information about colors and gem stones. It makes you realize we live in a world that is alive with atomic particles and their vibrations and influences on the human body. It is almost like reading about magic, but without the mystery produced by illusions. Any reader interested in these subjects will enjoy reading it. Even the scientific parts are really interesting.