Minerals can be classified in many different ways. The simplest and most common method is classifying the minerals according to their physical properties. This method is simply identifing the minerals based on common, easily recognized traits such as, color, size of grains, shape, and cleavage surfaces. Some physical properties are a little more difficult to recognize, but still are relatively simple characteristics to observe. These include, relative density, conductivity, smell, striations (scratches in the rock), hardness and streak. Streak is the property a mineral has when the powder of a mineral is a different color than the mineral itself.

Minerals can also be classified based upon their chemical make up. This method is more difficult than classifying by physical properties. It involves expensive and highly technical equipment to be able to detect the chemical makeup of a mineral. A method of X-ray analysis can be used to detect the chemicals in a mineral. This method consists of putting a sample of the mineral in an electron microscope fitted with an electron disperency spectrometer (EDS). An electron beam is aimed at the sample, as the electrons hit the sample electrons from the atoms inside the mineral are displaced by these new electrons from the electron beam. As the original electrons are kicked out of the sample it leaves its atom at a lower electron energy. This release of energy is then read by the EDS. The EDS converts this reading into millionths of volts. Each chemical has its own distinct amount of energy released when an electron is removed and this information can then be used to determine the chemical makeup of a mineral.

Crystal structure can also be used to classify minerals. There are five major differences in the crystal structures of minerals. These five basic differences are based upon the amount of linkages between atoms. The simplest structure is the tetrahedra. In this structure the molecule is made up of many independent molecules. An example of a tetrahedral rock is Olivine. The next crystal structure consists of Chains of tetrahedrons linked together. These chains are developed by linking tetrahedron end to end. The Pyroxenes are examples of single chained minerals. Amphiboles are an example of the third most complex crystal structure. This crystal structure is the double chain structure. It consists of single chains linked together side by side, creating chains that are double in width. Another way of looking at this is viewing single tetrahedrons as being linked together in two places. The fourth most complicated crystal structure are the sheet structures. These structures are made of tetrahedrons which have three of their four points linked to a separate tetrahedron which in turn is linked to two more tetrahedrons, as this process continues a sheet is developed in all directions of a plane. These structures have three points in which the tetrahedron is linked to other molecules. The Micas are an example of a sheet type structure. The most complex crystal structures are the framework structures. In these structures the tetrahedrons or molecules contain linkages at all points forming a 3- dimensional configuration. An example of this kind of structure are the Quartz and Feldspars.
 
 

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