Textbook Error Theory about Aragonite Structure

Science constantly discovers new theories and concepts, overturning erroneous theories and concepts. Textbooks never correct, fallacies are left to future generations. There are two erroneous theories about the structure of aragonite in textbooks: (1) The authoritative Chinese textbook “Outline of Shellfish Studies” by Zhang Xi and Qi Zhongyan believes that shells can be divided into three different crystal structures, with the middle layer being a prismatic layer that occupies the majority of the shell and is composed of calcite (cubic crystal system, hexagonal crystal cells). The shellfish academic community in China quotes many Japanese literature, and these theories may have been copied from Japan. (2) The geological crystallography book records that the structural physical properties of aragonite are unstable and will eventually transform into calcite. We use X-ray derivatives found that after a long geological time, aragonite not only did not become calcite, but also the grain is growing large: monocrystalline, calcite is still decreasing, calcite is changing to aragonite.