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Click Here For Best Selection Of High Quality Polarizing Microscope

Click Here For Best Selection Of High Quality Polarizing Microscope

The formula of mineral Bismuth is indicated by Bi or the Elemental Bismuth. Bismuth has an atomic number 83 in the periodic table of elements. Bismuth actually belongs to the Native Elements mineral class. The Native Element mineral class comprises over one hundred known minerals. Bismuth has been known since the ancient times. It was actually first discovered in the year 1546 at Saxony, Germany. In early 18th century, Bismuth was actually confused with lead and tin. Claude Geoffroy the Younger, a French scientist, was the first to show Bismuth to be a distinct element in the year 1753. The name Bismuth was actually derived from the German words white mass, Weisse Mass that is later changed to Wisuth and Bisemutum. This is an allusion to the white color of the pure Bismuth. Bismuth in its elemental form is considerably rare in nature. The laboratory grown Bismuth crystals however are the ones that is of growing interest in rock shops. Even though they are not really natural, these Bismuth crystals are actually found very interesting and are commonly exhibiting interesting and splendid microscope image under polarizing light microscope used in the field of optical mineralogy. These crystals are actually of interest to the mineral hobbyist and the same is true among others. These mineral clusters are commonly found displaying unique look that is very indescribable. Bismuth commonly exhibits color consisting iridescent metallic yellow, green and blue hues that appears very interesting under polarizing microscopes used in the field of optical mineralogy.


            The pseudocubic hopper crystals of Bismuth mineral are the ones that are of interest among the hobbyists. These crystals are always present on the Bismuth specimens that are produced in the laboratory. These hopper crystals, which are usually found exhibiting a fascinating image under petrographic polarizing microscopes for mineralogists, are considered as a unique crystallographic curiosity. These crystals are usually found having just the edges extending outward from the center of the crystal. And these habits are usually found leaving a hollow stair step faces between these edges. These hopper crystals are actually not seen in but the rarest of the natural mineral crystals. They commonly form because of the disparity of the growth rates between the faces of the crystals and the crystal edges.


            Bismuth minerals are commonly found in silver white color and are often found with a multi-colored iridescent tarnish when evaluated in reflected light of polarizing microscope used in the field of optical mineralogy. These Bismuth minerals are usually found exhibiting a metallic luster in reflected light of polarized microscopes for mineralogists. When Bismuth mineral specimens are evaluated between crossed nicols of polarizing microscopes used in optical mineralogy, they are commonly found having a perfect basal cleavage in one direction. The fracture that is found is uneven or jagged when it is examined under several adjustments on the aperture diaphragm of the petrographic polarizing light microscope used in the field of optical mineralogy. The hardness measure of Bismuth using the Mohs scale method is commonly found ranging from 2 to 2.5. Bismuth specimens are most commonly found leaving silver to white streak when they are rubbed on a white porcelain streak plate. The specific gravity measure for Bismuth mineral specimen is commonly found ranging from 9.7 to 9.8 grams per cubic centimeters, which is considered unusually heavy even for metallic minerals.


            Bismuth minerals are known to crystallize in the trigonal system of crystal formation. Bismuth mineral specimens are commonly found opaque in appearance. The crystal habit of Bismuth mineral usually includes massive foliated forms in natural specimens, which are interesting to view under polarized light microscopes. Some well-formed natural crystals also exist but are rather scarce. The crystals that are grown in the laboratory are usually displaying trigonal hopper crystals that are commonly found pseudocubic. This mineral Bismuth is commonly associated with other interesting minerals such as the ores of cobalt and silver that are usually found displaying magnificent images under polarizing microscope. These minerals are commonly found in hydrothermal veins like acanthite and cobaltite. Bismuth is also associated with Bismuthinite and their association is actually splendid and interesting to view under polarizing microscopes used in optical mineralogy. 


            When Bismuth minerals are evaluated under a petrographic polarizing light microscope they are usually found with striations on cleavage surfaces. The best field indicators of Bismuth minerals usually include cleavage, tarnish and density. For those laboratory grown crystals, the hopper crystal forms are actually unmistakable. Mineral Bismuth notably occurs naturally at some localities that commonly include Australia, Germany, some areas in the United States like South Dakota, Colorado and California as well as Devon, England and also in Bolivia covering areas like San Baldomero and La Paz.

Friday, January 15th, 2010 at 4:39 am
The Native Elements Mineral Class
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Click Here For Best Selection Of High Quality Polarizing Microscope