Page 2 shows photographs of the mineral in thin section viewed in both plane polarized light and crossed polarized light, the optical properties, and the minerals. In more complicated situations, numerical solutions are nec. Main index minerals list optical properties minerals have many interesting optical properties. The ordynary thin section is recomended for transmited light microscope observations. Laf3 thin films of different thicknesses were deposited on caf2 111 and silicon substrates at a relatively low substrate temperature of 150 degrees c. All the sections thin enough that you can observe under the microscope with transmitted light passing through section, from below they all thin enough that you can see. Minerals in handspecimen i itg itg getting to know you activity course overviewmineral properties in hand specimen. Contains over 200 photomicrographs, short chemical descriptions, and summaries of the optical properties of the various minerals.
Add or remove collections home rocks and minerals talc thin section reference url share. A detrital component in sedimentary rocks and as authigenic overgrowths. Thin section preparation petrography and mineralogy. The reflection at the surfaces is described by the coefficient of reflection or reflectivity. Theoretical considerations discussing the interaction of minerals and light, the properties of minerals in thin section, and the most practical aspects of optical mineralogy. Students look at mafic igneous minerals, learning to distinguish and identify them in hand specimen. Darkest when caxis parallel to vibration direction of lower polarizer blue tourmaline is darkest w caxis perpendicular to vibration direction of polarizer. Pdf a new approach to identifying grains in a petrographic thin section. Students look at some of the same minerals and others in thin section. This lesson will identify the different optical properties of minerals used in identification. Rock thin sections petrographic thin section preparation in optical mineralogy and petrography, a thin section is a laboratory preparation of a rock, mineral, soil, pottery, bones, even metal sample for use with a polarizing petrographic microscope, electron microscope and electron microprobe. My purpose was not to make a systematic presentation of rocks under the microscope but simply to show some interesting images of minerals and rocks. The properties of amphiboles, micas, pyroxenes, and olivines and an introduction to mineral properties in thin section dexter perkins, univ. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Changes in color under ppl with stage rotation are due to changes in the minerals orientation with respect to polarized light pleochroism useful for identification of some minerals for uniaxial minerals 2 hues. A photograph of a rock in thin section is often referred to as a photomicrograph. A last look at igneous minerals in thin section dexter perkins, univ. Ppt optical mineralogy powerpoint presentation free to. They note chemical and physical similarities and differences and why there are several varieties of minerals in each group. Addition and subtraction can be easily recognised by observing the changes in the colour sequence along the wedgeshaped edge of the grain. Optical properties glasses are among the few solids that transmit visible light thin film oxides might, but scattering from grains limit their thickness mica windows at acoma pueblo glasses form the basic elements of virtually all optical systems. When some opaque minerals are cut into thin sections they become translucent. Livelys mine golden rule mine regional and economic geology of the mount painter province. Optical mineralogy is used to identify the mineralogical composition of geological materials in order to help reveal their origin and. The first item to be introduced will be the petrographic microscope. Thin section preparation petrography and mineralogy examination.
Structural and optical properties of chemical deposition cds thin films. Colour of a transparent minerals in thin section is observed with analyser out position which then depends on the absorbtion of certain s of ew vibrating plane polarized white light emerging from the mineral. A thin section of an opaque mineral such as a metal will not transmit light, whereas a thin section of a. The purpose of optical materials is to provide a means of communication and technology transfer between researchers who are interested in materials for potential device applications. Geol 303a mineralogy although optical properties of minerals may be more difficult to determine. This organization and the many field, hand sample, and thin sections photos in color make this book interesting and one that students are more inclined to read. Anhydrite grain showing a colour sequence covering seven orders. Thin sections are prepared in order to investigate the optical properties of the minerals in the rock. Optical mineralogy and petrography serc carleton college. Now that you are familiar with how to use a petrographic microscope and some of the optical characteristics that can be observed for minerals, it is possible to identify minerals under the polarizing light microscope or at least to eliminate some possibilities.
This paper considers the use of the microscope in petrology, with particular reference to the polarizing microscope. This chapter deals with the optical properties of those minerals which make up the common rocks of the earths crust, the socalled rockforming minerals. Minerals in thin section is the perfect supplement for mineralogy, optical mineralogy, and petrography courses. A detailed, stepbystep account is given of the microscopic methods employed to determine the mineral constituents in a thin rock section. Guide to thin section microscopy extinction raith, raase, reinhardt january 2011 figure 4. Relief is a useful distinguishing property for the the igneous rockfroming minerals. When placed between two polarizing filters set at right angles to each other, the optical properties of the minerals in the thin section alter the colour and intensity of the light as seen by the viewer. Give a systematic description of minerals in thin sections using transmitted light. Properties of minerals in thin sections springerlink. They also look at a few of the minerals in thin section. Media in category optical mineralogy the following 43 files are in this category, out. A mineral whose optical properties are known can be accurately and quickly identi fied, however, by the immersion.
Minerals in thin sections have specific optical properties which are. Pdf files of lecture powerpoint slides are available here for downloading. These properties are extremely useful for identifying a mineral. Guide to thin section microscopyan excellent open source tutorial by michael. Add or remove collections home rocks and minerals muscovite thin section reference url share. Optical properties and identification amphiboles and micas optical properties and identification. Info 19 ucla petrography thin sections 20 wwwmincryst. In the lecture part of the course we have discussed the various optical properties of minerals. Optical materials has an open access mirror journal optical materials.
Introduction to mineralogy and petrology by cornelis klein and anthony philpotts, minerals and rocks are presented in the context of their geologic setting. Thin section of minerals set of 20 slides this collection contains 20 types of thin section of minerals slides types which is very helpful for age of 15 years and above. Blue pleochroism in thin section grain mount distinguishes from other amphiboles. At the completion of the course you should be able to identify 810 major minerals or groups of minerals.
Explain the optical properties observed under planepolarized light and. Pyrite is a very common mineral also one of the most common natural sulfides, and the most common disulfide, found in a wide variety of geological formations from sedimentary deposits to hydrothermal veins and as a constituent of metamorphic rocks. Info 19 ucla petrography thinsections 20 wwwmincryst. Photographs carefully chosen to depict features by which minerals may be recognized most easily. Students learn how to use a microscope to observe thin sections. Crystalline orthoclase can also be white, colorless, cream, pale yellow, or brownish red. Glaucophane has length slow, riebeckite length fast. To link to this object, paste this link in email, im or document to embed this object, paste this html in website. These traits include color, streak, luster, density, hardness, cleavage, fracture, tenacity, and crystal habit. Therefore it is essential to give an account of the optical properties of the principal minerals in soil including those derived from the parent. Several important optical properties are applicable to minerals and gemstones from a scientific standpoint. Pdf identification of mineral grains in a petrographic thin section. Optical properties of rocks and minerals the optical property of a mineral depends on how it interacts with light. This work is a part of petrology and helps to reveal the origin and evolution of the parent rock.
When new minerals, which are never observed to form at earths surface, form. The physical characteristics of minerals include traits which are used to identify and describe mineral species. Dark reddish brown to blackish brown, yellowish brown, rarely blue. The arrangement and relationships between minerals in soils is probably more complex than that found in most rocks since many types of mineral and their weathered products can occur in juxtaposition. Common in plutonic felsic rocks, as granites, granite pegmatites, syenites. A final lab exercise that uses the optical mineralogy skills learned in the previous labs and begins the transition to petrographic analysis of thin sections. The thickness of rock sample is 30 microns and the thin rock sample is covered with glass. Part three defining optical microscopy and light ray terms. In this edition of introduction to the rockforming minerals, most of the commonly occurring minerals of igneous, metamorphic and sedimentary rocks are discussed in terms of structure, chemistry, optical and other physical properties, distinguishing features and paragenesis. Optical properties chapter 9 minerals cambridge university press. Pdf optical and structural properties of laf3 thin films.
Animated pdfs showing optical properties of minerals john brady. Some of these are useful, some intriguiging, and some just fun. An important rockforming mineral, orthoclase is the potassiumbearing end member of the potassium sodium feldspar solidsolution series. Most commonly, rock and mineral samples are prepared as thin sections or grain mounts for study in the laboratory with a petrographic microscope. Almandine locality at alabanda, in asia minor, where garnets were cut and polished in ancient times. Jul 30 jul 31 3 aug 6 minerals in handspecimen ii itg itg introduction to mineralogy introduction to optical mineralogy aug 6 aug 7 quiz 1 4 aug intro to petrological microcopesminerals in thinsection i dc dc. The latter will involve the identification of minerals or specific optical properties for a given sample in a spotting quiz and the identification of the minerals within a single thin section. Optical mineralogy other properties that can be observed in ppl. Garnet mineral group name, from latin granatum pomegranate, the seeds of which it was thought to resemble. Reviews of the atlas of rockforming minerals in thin section. A study of these rockforming minerals entails their examination under the microscope, either as tiny grains or as thin 0. Mafic mineral properties and thin sections activities.
Orthoclase mineral physicaloptical properties, uses. Accompanying this exercise is a pdf which illustrates many of the features one can see in a thin section. When placed between two polarizing filters set at right angles to each other, the optical properties of the minerals in the thin section alter the colour and intensity. Optical properties of dielectric and semiconductor thin films 3 analytic solutions can be given if we assume that the incident wave is a pure wave and that the boundary layers are regular. We can do the same thing in a tsection by focusing and at a grain boundary.
For most properties, a low power objective is usually used up to x 10. Optical properties of minerals 12152009 physical characteristics of minerals i. Optical mineralogy is the study of minerals and rocks by measuring their optical properties. The s that pass through the mineral interfere and produce characteristic colour of the mineral. As different minerals have different optical properties, most rock forming minerals can be easily identified.
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