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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 chemical formula of mineral Nephrite is indicated by Ca2(Mg, Fe)5Si8O22(OH)2 or Calcium Magnesium Iron Silicate Hydroxide. Nephrite is actually a Silicate mineral. It is also a member of the Amphibole group of minerals. Nephrite is actually one of the mineral varieties of Actinolite. Nephrite is also one of the two jade minerals of Actinolite. They are most commonly found exhibiting splendid appearance when viewed with the aid of polarizing light microscopes used in the field of optical mineralogy. The other jade mineral is known as jadeite. Jade has been used as ornamental and religious stone for eons in China and Central America. They have gained deep significance in these places. The ones commonly used in China is the Nephrite jade although both jade minerals have been used in both regions. It has been know in optical mineralogy that nephrite is more abundant than jadeite. Nephrite has few color varieties known in optical mineralogy. These splendid cols are usually ranging from creamy white to green, which can be more majestically exhibited when viewed with the aid of petrographic polarizing microscopes used in the field of optical mineralogy. They are considered as relatively common mineral in some metamorphic rocks. A simple Actinolite occasionally forms interesting crystal habits and specimens that are more splendidly exhibited when viewed with the aid of polarizing light microscope for mineralogists. The crystals of this mineral species could be similar to that of the hornblende but they are always translucent or even transparent in appearance. Typically, they are found prismatic, flattened and elongated when evaluated with the aid of a polarized microscopes used in the field of optical mineralogy. Crystal specimens of Actinolite or Nephrite are commonly very interesting when viewed under polarizing microscopes.

           

Nephrite can be found green, white, or gray in color, which can be very interesting when viewed with the aid of petrographic polarizing microscopes for mineralogists. When Nephrite specimens are evaluated in reflected light of the polarized microscope, it is usually found exhibiting vitreous luster. Crystals are usually found translucent to transparent in appearance. The crystal habit of Actinolite, including Nephrite, as described in the field of optical mineralogy includes flattened prismatic and elongated crystal with a dome-like termination that is actually a two of the four faces of a prism. Nephrite is most commonly found fibrous and as a very compact mass.

 

Nephrite is known to crystallize in the monoclinic system of crystal formation. In the field of optical mineralogy, the monoclinic system of crystal formation comprises crystals having three axes of unequal lengths. Two of which are usually found in a position that is oblique or not perpendicular to one another. However, both of which are commonly found perpendicular to the third axis. It also shows perfect cleavage in two directions at close to 60 degree and 120 degree angles. Nephrite can be also found showing splintery to uneven fracture when specimen is viewed with the aid of petrographic polarizing light microscope. The hardness measure of the mineral when it is evaluated using the Mohs scale method is usually ranging from 5.5 to 6. The specific gravity measure of the mineral is usually approximately 2.9 grams per cubic centimeters to 3.3 grams per cubic centimeters, which is slightly above average for translucent minerals. Nephrite is most commonly found leaving a white streak when rubbed on a white porcelain streak plate.

 

Mineral Nephrite is most commonly found associated with other interesting minerals including quartz, epidote, lawsonite, and glaucophane. Nephrite is actually tough and stronger than steel. When evaluated under several adjustments on the aperture diaphragm of the petrographic polarizing microscope, mineral Nephrite is most commonly found showing moderate to high positive relief. When viewed between crossed nicols of petrographic polarizing microscope, Nephrite is commonly found showing a biaxial negative figure. Basal sections are usually showing symmetrical extinction with the slow ray parallel to the long diagonal. Elongation is usually length slow. The extinction angle usually shows a general decrease with the increasing iron content. The indices of refraction usually increase with the increasing iron content. The maximum interference colors in thin section are upper first order to mid second order. When specimen is viewed between crossed nicols of petrographic polarizing microscope, cleavage fragments usually yield highly off-center figures. The best field indicators of Nephrite usually include toughness, typical green color, hardness, and crystal habit. Actinolite notably occurs at some localities including the Lake Baikal Region in Russia, China, New Zealand, British Columbia, Canada, and Taiwan.



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Friday, May 15th, 2009 at 3:18 am
Category:
The Silicates Mineral Class
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