A Studentís Guide to the Genesis of the Agates, Jaspers, and Opals
By: Donald Kasper
This short summary work is a high-level review of the following that the author has found in writing his major works on the agates, jaspers, and opals:
∑ A concise definition of an agate, jasper, and opal.
∑ A definition of a chert and flint, and their comparison to agates.
∑ What is a chalcedony, and how does it differ from agate?† Hint: chalcedony is also banded.
∑ 12 major rules of agate genesis.
∑ What went wrong with the European classification of the agates.
∑ Agates are rocks formed in clay-silica systems.
∑ Agates form as calcium-silica-hydroxyl gels.† It takes carbonate to make an agate.
∑ The agates, jaspers, and opals are largely amorphous, not cryptocrystalline.