The book provides a comprehensive overview of the optical properties of minerals, correlating these properties with their structure and composition. It includes diagnostic criteria and a section on paragenesis, making it a valuable resource for petrologists. However, the production quality is generally pleasing, with minor misprints and inconsistencies in crystal figures. The high price is a significant drawback, making the series less accessible to individual readers. Overall, the book is an important contribution to the field, and the remaining volumes are anticipated with interest. Prof. George Gamow's biography of physics, "Men of Physics," is well-received for its instructive content and engaging style. It covers a wide range of topics, including the contributions of Archimedes, Kepler, Galileo, Newton, Faraday, Maxwell, Ampère, Oersted, Ohm, and modern physicists like Einstein and Heisenberg. The book is praised for its clear explanations and excellent illustrations, but it may be too advanced for those new to the subject. The author's goal of introducing physics to a broader audience is commendable, but the book's focus on entertaining anecdotes might distract less experienced readers. Prof. Cornelius Lanczos's "Linear Differential Operators" is a unique and detailed exploration of mathematical concepts with applications in physics and electrical engineering. The book covers interpolation, harmonic analysis, matrix calculus, function spaces, Green's functions, communication problems, Sturm-Liouville problems, boundary-value problems, and numerical solutions of trajectory problems. While the style is somewhat discursive, it is clear and well-structured, making it suitable for graduate students and researchers. However, the lack of references to original papers is noted as a notable omission.The book provides a comprehensive overview of the optical properties of minerals, correlating these properties with their structure and composition. It includes diagnostic criteria and a section on paragenesis, making it a valuable resource for petrologists. However, the production quality is generally pleasing, with minor misprints and inconsistencies in crystal figures. The high price is a significant drawback, making the series less accessible to individual readers. Overall, the book is an important contribution to the field, and the remaining volumes are anticipated with interest. Prof. George Gamow's biography of physics, "Men of Physics," is well-received for its instructive content and engaging style. It covers a wide range of topics, including the contributions of Archimedes, Kepler, Galileo, Newton, Faraday, Maxwell, Ampère, Oersted, Ohm, and modern physicists like Einstein and Heisenberg. The book is praised for its clear explanations and excellent illustrations, but it may be too advanced for those new to the subject. The author's goal of introducing physics to a broader audience is commendable, but the book's focus on entertaining anecdotes might distract less experienced readers. Prof. Cornelius Lanczos's "Linear Differential Operators" is a unique and detailed exploration of mathematical concepts with applications in physics and electrical engineering. The book covers interpolation, harmonic analysis, matrix calculus, function spaces, Green's functions, communication problems, Sturm-Liouville problems, boundary-value problems, and numerical solutions of trajectory problems. While the style is somewhat discursive, it is clear and well-structured, making it suitable for graduate students and researchers. However, the lack of references to original papers is noted as a notable omission.