Many appreciation books, many written by some collectors, have different interests and opinions, so there are many and miscellaneous books. Need systematic study, it is recommended to read systematic gemmology.

If you know systematic gemmology, it's not a big problem. Or there is a book "Study on the Main Producing Areas of colored gems in the World", which has just arrived and hasn't arrived yet. If it is good, please recommend it again.

There is also the book "Gems", a treasure sold more than a dozen pieces, with pictures and texts, especially the color classification of gems.

Finally, give a list of books: introductory reading: Tom Cruise's How Experts Buy Gems.

Learn Jade: Gemmology of Jade by Yuan, and How Experts Buy Jade by Tom.

Professional Textbook: Zhang Beili's Systematic Gemmology