A mineral section is normally viewed with so-called orthoscopic illumination or a bundle of approximately parallel light rays as described in the field of optical mineralogy. Polarizing microscopes has condenser system that produces strongly convergent light or conoscopic illumination when it is fully raised. Modern microscopes like the petrographic polarizing microscopes have extra […]

In an experiment in optical mineralogy, when a small clear cleavage rhomb of calcite is placed over a small, it can be noticed that there are two dots found. In the field of optical mineralogy, an explanation of the phenomenon holds true that the two images found represent the two separately polarized rays […]

In the field of optical mineralogy, a crystal of a certain mineral species can be evaluated in many ways. The first and most obvious step is actually the meticulous investigation of the physical appearance of the material through the analysis of its form and symmetry in hand samples. Of course, without setting aside […]

In the field of optical mineralogy, a zone is defined as a group of crystal faces that intersect in a set of parallel edges. These parallel edges have directions and it is known as the zone axis in the field of optical mineralogy. This zone axis is expressed as coordinates derived from Miller […]

Mineral crystals can be classified as belonging to one of the crystal systems determined in the field of optical mineralogy. This on the outset depends on the particular symmetry elements of the crystal. The crystal systems as determined in the field of optical mineralogy studies can be described in terms of the three […]

One of the aspects in optical mineralogy that introduces the general crystallographic concepts and terminologies required for optical works is the symmetry of crystals. Almost all crystals known to man posses a degree of symmetry, all of which are well-classified in the field of optical mineralogy and crystallography studies. This degree of symmetry […]

In the field of crystallography and optical mineralogy, a face or group of faces which have identical relationships to the crystal axes by the virtue of the crystal symmetry is determined as a crystal form. This crystal form can be expressed in terms of the Miller indices of one representative face, as described […]

In the field of optical mineralogy, it has been observed that many crystals break easily along smooth planes that are parallel to possible crystal faces and usually with simple index. This planes are determined in optical mineralogy are cleavage planes. Cleavage is said to be repeated by the symmetry of a crystal in […]

Optical mineralogy studies provide explanations on phenomena wherein the refractive index of anisotropic minerals varies with direction. And with the use of the petrographic polarizing microscope, it can be noticed that light passing through anisotropic minerals is resolved into two rays. Each of the rays represents a different refractive index as discussed in […]

In optical mineralogy, it has been found that light is generally polarized by anisotropic minerals in two rays vibrating at right angles to each other. It has been also studied in optical mineralogy that light from the polarizer is resolved into two rays by the mineral. This can be observed in general situations […]