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The Two-Volume Book Set Key Features


·         The first comparison of the agates, jaspers, and opals together studied as a complete series, with over 800 specimen photos.


·         The first detailed geologic look at the non-banded agates.


·         A thorough and modern look at geode and thunderegg formation.  The story of the geodes cannot be written until after the story of the agates is complete, so the two stories are told in a comprehensive, combined manner.


·         A discussion of why the agates, jaspers, and opals are amorphous rocks, not minerals, and all the geologic and identification and classification problems this has historically caused.


·         A complete dictionary or Lexicon of agate, jasper, and opal terminology of these rocks as they occur worldwide.  Over 570  agate, jasper, and opal terms are described in the Lexicon.  This also includes all the structures in the geodes and thundereggs.  This includes over 180 new structures are defined by the author to describe features are included.  The development of this Lexicon extensively reviewed conflicting, incorrect, and vague terminology.  An additional list of several 140 rejected terms is also included.


·         In Volume I, over 560 conjectures (theories) are presented for agate, jasper, and opal formation and on the nature of their inclusions and features.  It has several hundred tables and figures.


·         An identification key for naming the agates, jaspers, and opals can be used with the Lexicon.


·         Extensive photographs with the definitions for the rock types, inclusions, and features.  Words cannot describe everything, so numerous sample photographs are included.


·         The complete chemistry of formation of the agates, jaspers, and opals.  These rocks occur in very specific conditions that relate to their formation and appearance.


·         The complete geology of formation of the agates, jaspers, and opals, including many geologic settings that have not been previously documented or properly identified.


·         This is the first comprehensive look at all of the amorphous silicas that includes the agates, jaspers, and opals, reviewing them in a comprehensive, combined study.


·         This is the first comprehensive look at all of the related, amorphous rocks that have structures like the amorphous silicas, to use as models understanding the way these structures form.


·         This is the first comprehensive look at all the non-amorphous silicas that look similar to them, and how to identify them in the field.


·         This text focuses on the agates, jaspers, and opals of the Southwestern United States, which has perhaps half of the world’s silicate deposits.  These silicates occur in young volcanic rocks with many features and rock types missing from older silicate bearing regions, especially those of Europe.


·         A discussion of the critical role of the clay mineral bentonite (a decomposition mineral from volcanic ash) found with much of these rocks, and how it affects their formation that is missing from previous texts discussing the formation of these silicates.


·         The models of formation of the amorphous silicas are summarized in a set of conjectures that serve as conclusion points and future testable hypotheses.


·         The book does not ignore vein agates that are usually missing in other texts that focus primarily on nodular agates.


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