Leave a message

Click Here For Best Selection Of High Quality Polarizing Microscope

Click Here For Best Selection Of High Quality Polarizing Microscope

The chemical formula of Scapolite is indicated by Na4(Al, Si)12O24Cl to Ca4(Si, Al)12O24(CO3, SO4) or Calcium Sodium Aluminum Silicate Carbonate Chloride Sulfate. Scapolite minerals are actually Silicates minerals. They are most commonly used as mineral specimen and they are also used for gemstone purposes. Scapolite is actually a name of a series between the sodium rich mineral marialite and the calcium carbonate rich mineral meionite. The structure of Scapolites is very similar to that of the feldspathoids. Scapolite usually forms in metamorphic rocks from the alteration of plagioclase feldspars. Distinguishing Scapolite minerals from each other is quite difficult because they differ only very slightly in density and index of refraction. Scapolite is a Greek for shaft. This is most commonly found stubby to long prismatic crystals. Scapolite gems are not so well-known in the gem world. However, it can be also be found very attractive most especially when viewed in polarized microscope used in optical mineralogy field. Other gemstones have best features like fire and hardness however the colored ones lack them sometimes. Less transparent minerals can often be cut as cabochons that will often show a good Cat’s Eye effect or otherwise, the Moonstone effect.

             Scapolite is most commonly found white, colorless, greenish or gray in color. It can be also possibly found exhibiting yellow, brown, pink, reddish, violet or blue colors that can be very fascinating when viewed under polarizing microscopes for mineralogists. Scapolite is also most commonly found showing vitreous luster on freshly exposed crystals or surfaces but weathering may cause a dulling of the luster when viewed in reflected light of polarizing microscopes used in the field of optical mineralogy. Most crystals of mineral Scapolite are found translucent to transparent in appearance. Scapolite is known to crystallize in the tetragonal system of crystal formation. In optical mineralogy, this tetragonal system comprises crystals having three axes, which are all in a position perpendicular to one another. Two axes are usually found having the same or equal length.             The crystal habit of the mineral Scapolite usually include prismatic to stocky crystals terminated by a pyramid. Complete crystals of Scapolite rare and often the crystals will have distorted shapes with uneven faces. Scapolite is also most commonly found showing distinct cleavage in several prismatic directions producing a splintery almost fibrous appearance in cleaved massive specimens. Scapolite is also usually found showing subconcoidal to uneven fracture when specimen sample is evaluated with the aid of petrographic polarizing microscopes used in the field of optical mineralogy. The hardness measure of the mineral when it is evaluated using the Mohs scale method is usually found ranging from 5.5 to 6. Scapolite is most commonly found leaving a white streak when specimen sample is rubbed on a white porcelain streak plate. The specific gravity measure of the mineral Scapolite is usually found 2.5 to 2.7 grams per cubic centimeters, which is average value. Scapolite minerals will often fluoresce either orange, yellow or more rarely red under ultraviolet light. Its index of refraction also varies from 1.54 to 1.60. Scapolite is most commonly found associated with other interesting minerals including garnet minerals and some hornblende. The best field indicators of mineral Scapolite usually include cleavage, color, crystal habit, fluorescence, cleavage surface features and hardness. Scapolite notably occurs at several localities including Norway, Italy, Mexico, Brazil, Switzerland, Burma and some areas in the United States.



Author:
Time:
Sunday, August 30th, 2009 at 3:46 am
Category:
The Silicates Mineral Class
RSS:
You can follow any responses to this entry through the RSS 2.0 feed.
Navigation:
Click Here For Best Selection Of High Quality Polarizing Microscope