gems, jade, Fischer

Fischer presents a chronological history of the introduction and development of microscopic methods in mineralogy, petrography, and paleontology. He traces early observations with magnifying instruments and microscopes and the gradual application of these techniques to minerals, rocks, fossils, and thin sections, discussing the contributions of numerous investigators and improvements in instruments and observational methods. Particular attention is given to the increasing recognition that microscopic examination could reveal structures, inclusions, textures, and mineral constituents that could not be distinguished macroscopically. The work documents an important methodological transition in nineteenth-century mineralogy and petrography, when microscopy was becoming an established analytical technique for identifying minerals and investigating the composition and structure of rocks.