Mineral lepidolite Essay

 

 

Abstract:

Chemically Lepidolite are formed by the combination of 5 percent of Li 2 O, 12 percent of K 2 O, 26 percent of Al 2 O 3, 51 percent of SiO 2, 1.5 percent of H 2 O, in addition to 4.5 percent of F. “The term Lepidolite is derived from the Greek word lepidion, which means scale and litho, which means stone they belong to a group Mica.” (Julie et al., 1998) The structure of Lepidolite shows that their cell dimensions measured from precession photographs are a=5.205, c= 29.77A, if we talk about stability then it shows that it is stable at the comparatively very low values of equilibrium constant. Lepidolite is very beautiful stone with many economical uses and mostly found in Zimbabwe, Australia as well as South Africa.

Introduction:

The mineral lepidolite fits in to the Silicates mineral category. It is usually pale pink to violet in color, the luster of lepidolite is vitreous on the way to translucent and the crystals of Lepidolite are translucent to semi-transparent; it is very beautiful and can be used for decoration purpose. The chemical composition of Lepidolite is pedestal on the subsequent elements, Alkaline fluosilicate of lithium, potassium, and aluminum, 5 percent of Li 2 O, 12 percent of K 2 O, 26 percent of Al 2 O 3, 51 percent of SiO 2, 1.5 percent of H 2 O in addition to 4.5 percent of F are found in chemical composition of mineral lepidolite, if we talk about the structure of lepidolite then we come to know that the crystals of lepidolite are not doppelganger as a result of this study the cell dimensions measured from precession photographs are a=5.205, c= 29.77A, the stunning success about structure  of this mica is the result of Stevens’ examination. The studies shows that lepidolite (KLi2Al (Al, Si) 3O10 (F, OH) 2) is stable at the comparatively very low values of equilibrium constant.

The geological occurrence of lepidolite shows that it is in large quantity found in Zimbabwe, Australia and Africa. While discussing about its economical uses we come up with the conclusion that lepidolite is of great use economically as it is being used in making lamp shades to exceedingly discriminating sieve for take into custody cesium ions. So this article has discussed all the facts and concerns about Lepidolite.

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Mineral Lepidolite:

“Mineral Lepidolite is also a constituent of the Micas Group of minerals. Lepidolite is for the most part well thought-out as an ore of lithium. In addition to as an ore mineral, it is frequently found demonstrating astonishing manifestation when scrutiny under an ore polarizing light microscopes.” (Mines, Geologique, Fontainebleau, April 2006) Lepidolite is infrequent, occurring approximately absolutely in structurally multifarious granitic pegmatites, generally in substitution component. Universal acquaintances are quartz, cleavelandite, alkali beryl, as well as alkali tourmaline. It is a commercial foundation of lithium, universally used unswervingly in lithium bifocals in addition to other ceramic products.

Let us have looked on few examples of dioctahedral and trioctahedral Micas, the examples of dioctahedral micas, Aluminoceladonite (Potassium Aluminum Magnesium Iron Silicate Hydroxide),Boromuscovite (Potassium Boro-silicate Hydroxide),Celadonite (Potassium Iron Magnesium Silicate Hydroxide),Chromphyllite (Potassium Chromium Aluminum Silicate Hydroxide Fluoride), and the names of few Trioctahedral are Annite (Potassium Iron Aluminum Silicate Hydroxide) ,Aspidolite (Sodium Magnesium Aluminum Silicate Hydroxide) ,Eastonite (Potassium Magnesium Aluminum Silicate Hydroxide

“Mineral Lepidolite is also used as an ornamental stone furthermore it is often originated exhibiting superb outward show when vision beneath gemological microscope. The crystalline arrangement of mineral lepidolite is monoclinic, it is more often than not found in violet to pale pink or white color in addition to hardly ever gray or yellow in manifestation.” (Mines, Geologique, Fontainebleau, April 2006)

Chemical Composition of Mineral Lepidolite:

The chemical composition of Lepidolite is pedestal on the subsequent elements, Alkaline fluosilicate of lithium, potassium, and aluminum, the detailed study shows that it is composed of 5 percent of Li 2 O, 12 percent of K 2 O, 26 percent of Al 2 O 3, 51 percent of SiO 2, 1.5 percent of H 2 O in addition to 4.5 percent of F. These all compounds combine together in the given proportions to form mineral Lepidolite. The chemical formula of Mineral lepidolite is K(Li,Al)3(Si,Al)4O10(F,OH)2  (Mines, Geologique, Fontainebleau, April 2006).

Structure of the Mineral Lepidolite:

The mica minerals “are sheet silicates with a three-layer sheet arrangement furthermore by means of moreover K+ or Ca++ and Na++ sandwiched between the layers.”  (Mines, Geologique, Fontainebleau, April 2006) Mica minerals have an exceptionally thin flake-like configuration. For that reason these minerals are very bendable in addition to easily broken. The credentials of mica are customarily not that a great deal of a predicament. The just right cleavage in addition to the shape of the crystals more often than not is a dead give away. It also has a clearly identifiable elastic snap in the cleavage flakes. Even though the minerals are thin, they are surprising resistant to high temperatures and pressures. The arrangement of the minerals fundamentally is set up the equivalent way that a building would be assembled; only one layer at a time is observed. Aluminum, by the side of alkalizes, magnesium, along with ferrous iron, are what give the micas their well defined makeup.

The lepidolite micas have made available such evidences from an ordinary group for structural reading, symbolize, seeing that they do a number of heaping dissimilarities in addition to organize provision. These variations have facilitated to elucidate structural associations which are important to the mica group as a whole. This report recapitulates crystal structure examination of a lepidolite having a 3T heaping display and a symphony able-bodied surrounded by the polylithionite assortment.

The masterpiece of this mica as derived from Stevens’ examination provides the details.

He assumes that the calculation of the valences of all cations except hydrogen will be 44. The symphony in stipulations of polylithionite, trilithionite, muscovite ultimate junctures members, Foster, 1 960, places this lepidolite close to the polylithionite closing stages constituent, with a relative ratio PL 84.8. TL 12.7. MS 2.5. Symmetry and cell dimensions were stead fasting on 0.5mm squares incise by means of a line saw on or subsequent to the high quality 0 .1mm thick micas sheet. This mica is uniaxial, which put forward at the symmetry is trigonal or hexagonal. Zero and first-level c-axis precession photographs are indistinguishable at intervals of 120′ in the region of the dial axis furthermore be evidence for the trigonal nature of the mica. Precession photographs of levels at a 90 degree angle to the trigonal (c) axis (a*a*) show six crease symmetry on the

Zero level and three fold symmetry on upper level. Giiven and Burham gives the axes by their practice, they favored the axes to be the 5.24 dependable with the performance, they also stated that, the continuation of manifestation by means of indicator at the same time subsequent the regulations (h – k) = 0 and (k + l) is not equal to 0 in addition the concurrence connecting premeditated and experimental configuration features the length of the (10/) row points in the direction of that the crystals are not doppelganger. As a result of this study the cell dimensions measured from precession photographs are a=5.205, c= 29.77A, and the cell dimension measured from single crystal diffractometer are different from the described above. (Galliski, Peter Germy, June 2006).

Stability Relation of Lepidolite:

Method used for determination of stability:

Customary hydrothermal measures were pursuing throughout this investigation. Scamper resources were preserved in gold or else platinum capsules. A little experiment was executed using the fluorine buffer modus operandi by Munoz and Eugster in the year 1969; experiments were consummate in stellite “cold seal” rod bombs which were on the exterior heated. Chromel-alumel thermocouples standardize in opposition to the liquefying points of NaCl (800.5″C.) and Zn (419.5’C.) scrutinizes the bomb temperature.  a bourdon-tube gage was used during the experiment to measure total fluid pressure, runs were extinguished either by subordinating the pressure container into a bucket of cold water or by propelling compacted air onto the hot bomb. All run products were X-rayed using powder difiractometer techniques and were investigated optically (Galliski, Peter Germy, June 2006).

Stability of the lepidolite:

By presumptuous idyllic integration in an HF-H2O gas stage, in addition to by means of fugacity coefficients for HF derived from critical constants, it is believed that one can calculate an fairly accurate fugacity of HF  around 200 bars at 2 kbar 800’C. By the means of mole fractions, the H2O/HF ratio in the gas phase would be about 20: 1. This calculation predicts only the maximum in view of the fact that it is supported on total putrefaction of the mica, moreover on little or no fluorine in the liquid phase. When one of the reaction which was predictable in shaping the stability at high temperature does not occur at the time when experiment was performed with high values of equilibrium then it is believed that lepidolite (KLi2Al(Al, Si)3O10(F, OH)2) is stable at the comparatively very low values of equilibrium constant (Galliski, Peter Germy, June 2006).

 

Physical properties of lepidolite:

1.      Usually pale pink to violet in color,

2.      The luster of lepidolite is vitreous on the way to translucent.

3.      “The crystals of Lepidolite are translucent to semi-transparent.” (Louis Raimbault, April 1998)

4.      The crystalline composition of lepidolite shows that it is monoclinic 2/m.

5.      Their crystal habit consists of tabular to prismatic crystals with a well-known paranoid termination. “Lepidolite’s four prism faces as well as two pinacoid faces form pseudo-hexagonal crystal “books”. The sides of the crystal often tend to taper. Also granular rock forming masses.” (Louis Raimbault, April 1998)

6.      The cleavage of lepidolite is ideal in one bearing constructing thin sheets or flakes.

7.      The fracture is not willingly experiential outstanding to cleavage but is not smooth.

8.      The hardness of lepidolite is estimated to 2.5.

9.      “Their specific gravity is approximately 2.8+ (average).” (Louis Raimbault, April 1998)

10.  They have a white streak.

The economical uses of Mineral Lepidolite:

Lepidolite has a lot of uses in our globe to be acquainted with it today. Lepidolite can be bringing into being in the manufacture of lamp shades on the way to insulator covering for wires (Louis Raimbault, April 1998). Here are few more uses of Lepidolite in our society today,

It is used to make narrator diaphragms, blizzard deteriorates, they are also used in manufacturing of heat protector, paper, along with gesticulate plates. A good number of paint these days can be added to lepidolite. It is now even being studied for its uses with nuclear actions as well. Mica is found in rubber products, oil well bradawl additives, in addition to in roofing products. When nuclear reactors seep out they discharge radioactive isotopes cesium-137 into the air. Two researchers have now exposed a form of mineral lepidolite that acts as an exceedingly discriminating sieve for take into custody cesium ions. Furthermore, mica capacity helps us to be bright to securely clean up radioactive spill out with out responsibility any destruction to the environment. So the above discussion shows that mineral lepidolite has many in economy therefore it is considered very important in the economy (Louis Raimbault, April 1998).

Geological occurrence:

The largest mica mine is found in Zimbabwe located about 72 km east fort Victoria, a number of mica occurrences are found on Etuis, which are connected by means of pegmatite dykes in addition to which were excavation for manufacturing mineral use. These are light muscovite mica, which is mainly used in electronics and as a high fire resistant heat isolator. Lithium containing mica (lepidolite) however also occurs in the northeast of the farm, which is used as lithium ore and as such is of some consequence for the industrialized of out of the ordinary metal material for illustration in aviation. In Africa few productive areas occur in Mozambique, Uganda as well as Rauanda in these places only lepidolite is exploited commercially, the most important Lithium bearing district is found in Western Australia. So it is believed that Lepidolite is found mostly in western countries. (Kennedy)

Conclusion:

We concluded that mineral lepidolite is very fine-looking, usually obtained in light pink to violet color, has great economical uses now-a-days.  Lepidolite can be use in the manufacture of lamp shades on the way to insulator covering for wires. It is also believe of peoples that lepidolite in future can be used as an exceedingly discriminating sieve for take into custody cesium ions therefore it is considered very important economically, while on other hand if we look on its composition so it is formulate by complex mixture of elements therefore it is considered as very unique others. This article also concluded that lepidolite is very unique and precious mineral but hardly found it is believed that the largest mica mine is found in Zimbabwe located about 72 km east fort Victoria, a number of mica occurrences are found on Etuis also in Africa few productive areas, occurred in Mozambique, Uganda as well as Rauanda in these places only lepidolite is exploited commercially, the most important Lithium bearing district is found in Western Australia. So overall this article has concluded all the details about this precious stone and has also narrated its uses and the places where it can be find so this peace of writing is giving complete information about Mineral Lepidolite.

 

 

 

 

 

 

 
References:

Louis Raimbault, Composition of complex lepidolite-type granitic pegmatites and of constituent columbite-tantalite, Chedeville, Massif Central, France, The Canadian Mineralogist; April 1998; v. 36; no. 2; p. 563-583 retrieved from http://canmin.geoscienceworld.org/cgi/content/abstract/36/2/563?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=or&field_name=fulltext&field_value=geological+occurence+lepidolite&searchid=1&FIRSTINDEX=0&sortspec=relevance&fdate=12/1/1957&tdate=8/31/2007&resourcetype=HWCIT.
Julie B. Selway, Petr Cerny, and Frank C. Hawthorne, Feruvite from lepidolite pegmatites at Red Cross Lake, Manitoba, The Canadian Mineralogist; April 1998; v. 36; no. 2; p. 433-439 retrieved from http://canmin.geoscienceworld.org/cgi/content/abstract/36/2/433?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=or&field_name=fulltext&field_value=geological+occurence+lepidolite&searchid=1&FIRSTINDEX=0&sortspec=relevance&fdate=12/1/1957&tdate=8/31/2007&resourcetype=HWCIT.
Miguel Angel Galliski and Petr erny, GEOCHEMISTRY AND STRUCTURAL STATE OF COLUMBITE-GROUP MINERALS IN GRANITIC PEGMATITES OF THE PAMPEAN RANGES, ARGENTINA, The Canadian Mineralogist; June 2006; v. 44; no. 3; p. 645-666; DOI: 10.2113/gscanmin.44.3.645 retrieved from http://canmin.geoscienceworld.org/cgi/content/abstract/44/3/645?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=and&field_name=fulltext&field_value=mineral+lepidolite&searchid=1&FIRSTINDEX=0&sortspec=date&fdate=12/1/1957&tdate=8/31/2007&resourcetype=HWCIT.
Bruce A. Kennedy, Surface mining, Chapter 1 retrieved from , http://books.google.com/books?id=qJJrYnpT2pYC&pg=PA196&lpg=PA196&dq=geological+occurrence+lepidolite&source=web&ots=Yy9NtN8wqi&sig=_YH-pVeAtAazjE_Xk4AIWeEbP_Q#PPA2,M1.