Genesis & Classification of Agates & Jaspers: A New Theory
by Marco Campos-Venuti.
From the back of the book:
"This book shows a new geological model that explains the formation of most of the microcrystalline and amorphous varieties of silica. It has been written for the collectors, the geologists, and for the curious, analyzing many collectible varieties of jaspers, agates and chalcedonies. The use of a geological and stratigraphic innovative approach to the theme, leads to the consequence that most of the concepts are original. The most important conclusion is that silica varieties take their origin in a meteoric environment with a strong influence due to the weather and the alternation of dry and wet seasons. Uncountable situations are possible due to the many parameters such as the host rock, the pH of the water, and the latitudes, that explain the numerous existing varieties of silica. Explication of the involved phenomena is ruled out with the help of an endless number of pictures and diagrams that capture and maintain the attention of the reader."
159 pages
Softcover