Healing Crystals: The A-Z Guide to 430 Gemstones by Michael Gienger is a pocket-sized, comprehensive reference guide profiling 430 crystals with color photos and concisely explained healing properties, mineralogy, and mental/physical effects. It is designed for both beginners and experienced users to easily identify stones and understand their unique energetic applications. This book is a popular choice for identifying crystals and understanding their traditionally recognized healing properties.