This book contains a wealth of information on all aspects of the mineral feldspar, and its varieties. Designed for the beginner or experienced, it will greatly assist those wishing to find out more about how to correctly identify feldspar minerals. Each feldspar variety is shown, with information on the physical and optical properties. There is also details on the correct readings for feldspar and its many varieties, from various gemmological instruments, such as chelsea filter, spectroscope, ultra-violet light, refractometer, polariscope, to name just a few, which will aid in accurate identification. This book will also prove useful to the gem fossicker in the field as it includes useful visual information which can also be used to determine correct identification.