I have received a lot of books lately and it is complicated to read them all at once, but I will try to summarize here the interesting ones. Today I start with the latest book by Theodorus Themelis about the heating of corundum. If you have Ted’s previous books, there are a lot of new things! First, and I think the idea is great, is that the book is provided in 7 small volumes, each with its subject. Why do I think it is great? Because if the author wants to add some arguments to his book in the future, we will have to change only 1 volume concerned, we will not have to reprint a whole complete book, so the cost will be much lower, and theoretically it would be faster, no need to wait 10 or 15 years between one book and the other! The whole 7 volumes are, if I counted correctly, a little more than 400 pages. Who should buy this book? Well, without thinking about it I would say everyone, but it would especially be those who want to discover the secrets of heating corundum, it is the only book that approaches the subject with so much technical data, but be careful, it is very scientific, because it explains everything, really all the aspects of this subject, it is complicated even for very good gemologists, it is more about chemistry. On the other hand, even a gemologist who does not want to heat his stones should have this book, because there is so much information that you can’t find anywhere else, and it allows you to better understand how the different inclusions change with different treatments, and believe me, sometimes there are surprises, what we learned at school is only a small part of reality… In summary, we are lucky that the author shares his decades of experience with us, because it is a complicated subject and it is difficult to find any information. I forgot, 5 other volumes are in progress, they will talk about heating with flux, diffusion with beryllium. – Nicolas Francort, Niru Gems, BKK, Thailand (Sept. 2024)