Mineralogical Tales of Missing Links and Puzzles
The sciences of mineralogy and petrographic microscopy have had a number of challenges to share and relinquish before they all came into a state of success and operational constancy. When it entered into a transitional phase at an understandably downside route, small blots of difficulties, encountered in microscopically correlating a reflected light from a transparent mineral into its corresponding identification, proved to be too big an obstacle to hurdle. At the zenith of these concerns in the field of microscopy, therefore, not just a single optical instrument was tapped to answer the heed for a descent mineralogical research instrument. In fact, four ocular tools have been essential to the progress of the discipline of mineralogy as we discern it today. First is the crystallographic goniometer. This particular instrument is used to obtain statistical counts of the external morphology of a crystal. Second is the well-celebrated petrographic microscope. Arguably regarded to be the topmost visual tool in terms of caliber and importance, such is employed to determine the optical characteristics of a given mineral under study. Next is the X-ray diffraction camera which is used to evaluate the internal arrangement of the mineral within the atomic level, and finally, an electron microprobe was given birth so as to analyze the chemical composition of a research object. Every single count of these instruments has been subjected through successive phases of advancements and upgrading that have improved its ability for obtaining the utmost amount of information possible for that general method.
Since it was outspokenly regarded that optical mineralogy is a daunting and toil-laden sub-field of mineralogy, mineralogical experts, who work on petrographic microscopes and features, came out with groundbreaking discoveries in some of the crucial facets of a mineral. They brought into the open that minerals have some considerable amount and degree of effects on light passing through them in notable ways. Most of the revealed information published by these petrographic microscopists were centered with dichroic and trichroic minerals. Respectively, particular examples such as tourmaline and iolite (cordierite) were proven to have shown varying colors when analyzed from different paths. Another generally identified characteristic is that of twofold refraction which is displayed by the doubling-up of an image observed through a cleavage piece of calcite. However, experts working on petrographic microscopy found out that the two images were polarized in dissimilar pattern of refraction.
Other ocular distinctiveness that once clogged a fluent-bound flow of microscopy was the vagueness in understanding the exact mechanism of the speed of light and its alteration as it passes through a spectrum of a given crystal. It was revealed by mineralogists and petrographic microscopists that light, which originally moves at 186,000 mps (miles per second) in a vacuum, passes significantly slower when it travels through a crystal. According to studies conducted in the field of petrographic microscopy, such tendency of the crystal is attributed to its structure and composition, and hence, cause it to pass through at varying pace in different tracks through the same crystal. To remedy this concern, mineralogical experts came up with an added feature to a petrographic microscope by setting up a polarization plane of a light beam which allows it to be revolved around its own axis of travel as it passes through a crystal. These ocular effects then served as a sort of a fingerprint and petrographic microscopists concerns on a crystal’s distinctive mark has been long solved through the ages and has just been considered to be a part of mineralogical history.
