Optical Quartz in Maine

Prepared for the Geological Department

At The University of Maine Augusta

Independent study

By

Eric W, Bradstreet

Student, University of Maine Augusta

24 June 2000

Eric Bradstreet

P.O. Box 1332 ~ Waldoboro ~ Me. 04572

Home Phone 207-832-2159 ~ Email [email protected]

Bob Doyle

258 Civic Center, UMA

Augusta, ME. 04330

Dear Professor Doyle,

I am very intrigued by the challenge we discussed on June 13, 2000 on the subject of the localized optical quartz in Maine. Since getting the go ahead for this study I have gathered as much research that has been done in this area, in hopes to get a feel for the definition of optical quartz. The research has not revealed a clear definition in terms of chemical components and structure. The study ahead will provide a clearer definition of optical quartz.

My research will include a collaboration of theory around this topic. The forces need to create such an environment that produces this result (optical quartz). Also it will include the chemical composition need for optical quartz.

The study will provide an understanding of the Sebago Batholith and its intricate piece in the development of this localized occurrence. The aspects of geology that will be discussed are magma, solution composition, Granite Plutons, and Mineralology.

Some historical information will be discussed, but the depth of the study will take a scientific approach!

For a more in-depth look at the organization of this research I have provided an outline index.

Sincerely,

Eric Bradstreet

Student, University of Maine Augusta

EB

Acknowledgments

I would like to recognize the assistance I have received in this study. I want to thank Bob Doyle, science professor at University of Maine at Augusta for the opportunity of doing this study. His experience in bedrock geology of Maine has helped this study immensely. Appreciation also goes to the Geological Department of Maine. Their years of work and compiled information have been a great asset. I also acknowledge credit too Woodrow Thompson, of the Maine Geological Department for assisting in the direction of information and is wide knowledge of minerals in Maine.

Outline

Optical Quartz and its Localized Occurrence

I). Preface

II). History of optical quartz in Maine

A. Era of mining quartz

B. Uses of optical quartz

C. Sebago Batholith

D. How the melting origin affected and interacted with the country rock

III). Geological setting

A. Brunswick Topsham

B. Alburn

C. Alburn - Sangerville formation

IV). Pegmatite

A. Magma

B. Arteries

C. Veins

D. Solidification

E. Pegmatite Core Dynamics

V). Overview of quartz and its properties

A. Outline of quartz

B. Applying Paulings rule to optical quartz

C. How did these conditions reach the optimum environment for optical quartz?

D. More discussion on solidification

E. Past studies that have been done with quartz

F. Today’s studies

VI). Summary and Conclusion

A. Tying all the data together

B. Reiterating the key issues that brought forth scientific evidence

C. Conclusion of the study

Preface

This study focused toward optical quartz and is formatted for the general science students. The study will explore the optical quartz occurrences in western Maine.

The work that has been cited in this study is referenced by Author’s last name at the end of this document.

Note: The author's background in geology extends over a 5-year period. Theories set forth in this study are theories of the author.

The study of the earth's rocks is known as the science of geology. This science covers many fields of expertise, earth science, mineralogy, chemistry, physics, and technology (mapping, compiling data).

This study will observe the environment best conducive for optical quartz [SiO2] One of the most abundant mineral in the earth and has many different spectrums [see, pg.13, Quartz properties]. In order to understand why quartz produces many spectrums, it is necessary to explore its environment. This will encompass bedrock geology, thermal geology, and magma.

One particular type of quartz used in industry is optical quartz. The study will define the term optical quartz. Various studies of others work in this field will be used to compile a synopsis. However the new work in this study will come from the focus on the eastern flank of the Sebago Pluton, located in South Western Maine. It is the hope of the author that upon reading this study one will go away with a clear understanding of optical quartz and its occurrence in Maine.

History of optical quartz

Era of mining quartz: During the beginning of the industrial age, quartz became part of the fabric of the electrical industry. In an interview with Geoffrey LaChance the owner of the LaChance quarry located in Brunswick Maine, He remembers the mining era very well. Geoffrey tells about when he was just 7 years old, in 1919, the American Glue Company began to purchase quartz from areas in Maine. The use of this quartz was to make sandpaper. He remembers it like yesterday, the hard labor of extracting quartz was time consuming and labor intensive. The price per pound then was unknown to Geoffrey. It was, F. Thomas LaChance, Geoffrey father who had opened the quarry. No other quarry produced the large amounts of fine quality quartz like the LaChance quarry did [Photo on right]. The quarry closed in 1922 and reopened in 1926 when the General Electric Co. (GE) began to purchase quartz for its optical value. “The price was $10.00 a ton”(Lachance, 2000. pers. comm.). Prompting other area prospects to open quarries that were previously mined for gems or feldspar and began mining them for quartz. Some of the other quarries that produced and sold optical grade quartz to GE were, “The Pulsifer quarry located in Auburn Maine, which was mine for gemstones in 1901” (US Bureau of Mines, 1975. p. 72). “Norway Maine was another location that GE had bought optical quartz from; the quarry opening was on cobble hill” (LaChance, 2000. pers. comm.). In the report Maine Pegmatite Mines and Prospects, Maine Geological Survey of 1957 reported GE also operated its own quarries in Albany and Buckfeild Maine, both quarries produced optical grade quartz. Upon investigation of other quarries with in the boundaries of the eastern flank of the Sebago Batholith; much of the quartz is adulterated with the exception of the LaChance quarry. It will be to our benefit to investigate why the quartz became adulteress in these areas and not so adulteress in other areas of purchasing. The issue of adulteress quartz will be discussed in-depth later in this study.

Uses of optical quartz: In 1921 Professor Walter G. Cady discovered that quartz could be used to control radio oscillator circuit (US, Bureau of Mines, 1975 p. 881). In1926 GE began to buy optical grade quartz. The quartz was sorted at the quarries by looking for clarity within each piece. 100,000 tons were extracted from the LaChance quarry, but only 8-10 tons were shipped to Lynn Massachusetts (LaChance, 2000. pers. comm.). There the quartz was sorted again and only the finest of the quartz was sent to GE’s science department in Schenectady New York. The remainder was used for electrical purposes. Elihu Thomson, a scientist, head of the science department in Schenectady was attempting to use the quartz to build a refractive lens. His attempts failed, because the process thus far, was to solidify the quartz and pour into a mold, but upon cooling the quartz would crack. What Elihu developed was Pyrex. The composition of Pyrex is water and quartz fused together. “Fused Silica is synthetic molten quarzglass. The very good optical transmission characteristics in the UV (ultraviolet) range besides a high transmission up to the infrared are only two of the unique properties of this material” (Prazisions, 2000). The properties used here describe the term optical quartz by the transmission of light patterns; the UV range. The atomic properties of optical quartz will become clear throughout this study.

Geology of the Sebago Batholith: The Sebago Pluton is a two-mica granite that intruded the metasedimentary rocks of the Central Maine Terrane around 292 Ma (Behn, Eusden, Notte, 2000). “The ambient temperature at emplacement of the Sebago Batholith is constrained to be approximately 350 degrees C and 500 degrees C” (Tucker and Marvinney 1989. vol.3 p. 27). Tucker and Marvinney also state that the average discordance between muscovite and biotite ages is 5 ma implying that, on average the region cooled at a rate of 15 degrees C/MY between approximately 245 Ma and 230 Ma. Gauging the time that cooling took place determining when each mineral solidified out is part of the process of developing a theory of what conditions were present to form the optical quartz surrounding the Sebago Batholith.

The Sebago Batholith is surrounded by many small granite plutons. Perhaps these smaller plutons are from the origin melt of the Sebago Batholith.. This research includes the surrounding pegmatite, the pegmatite’s are known to be granite pegmatite in this region of Maine. This would suggest that the batholith be not constrained to the Sebago area. Although the textures and some composition are different and irregular surrounding the batholith, they are more alike then different; exspecially in regards to mineral composition. A study of these rock structures has shown that the two mica type of the Sebago Batholith is consistent with the surrounding pegmatite. At the center of the intrusion the texture of the pluton is on a micro-scale to a granular scale. But as we move outward from the core solution the texture changes. The granite pegmatite of western Maine have a larger crystal structure then the pluton localized in the Sebago area. The mineral composition changes and differs from the core solution of the pluton in these surrounding pegmatite’s.

There have been many theories why the structure differs and many studies have been done to prove that they differ; not excluding the work that has been done to show their likeness. “One man who has studied these granites and pegmatites has theorized that the inconstancies reflect that the core solution and rare earth elements in the pematites are caused by the re-melting of the metamorphic rock” (Laverdeire, 2000.pers. comm.). This suggests that the batholith extend outward into the country rock. Figure (A ) shows the positioning of solutions developing within country rock and its fracture-filling replacement. “These rocks collectively represent an intrusive history spanning time from the early Devonian to the Cretaceous.… within an estimated area of 2000 km 2” (Hussey, 1981.File. no. 81-29).

Figure A, by: Cameron, 1942-1945, Pegmatite Investigation:

New England Geological Survey, Professional Paper 255 P. 27

Other smaller granite bodies are present in the surrounding country rock. The origin is from the core of the Sebago Batholith according to this study (see figure B). The evidence that shows this is that the mineral composition is much the same in other plutons. If we exclude the fact that adulteress rock (adulteress rock , solution carried through metamorphic rock contaminating the origin) being carried into these surrounding plutons then perhaps what is left is the same core solution of the Sebago Batholith. “Geophysical evidence suggest that with the exception of the outer core the earth normally consist of solid material. Thus any magma must originate by the melting of preexisting solid rock” (Cox, 1979 p.5). Gravitative separation, flowage differentiation, and systems involving liquid and vapor are models in which one will arrive at these determinations.

Needless to say the rock we see today has undergone many changes while spanning time. The primary composition has not changed since emplacement of these bodies. Some alteration has occurred due to movement of tectonic plates, fractures, cracks, and minor re-melting due to pressure.

Diagram By: Bradstreet

Geological Setting

Brunswick: (see figure C) The Brunswick area is dated Cambrian --Ordovician, and is situated within the Cushing formation (Geologic Map. Maine, 1985).

In the Yarmouth-Brunswick-Garndiner area the cushing formation can be divided into the Richmond corner, Mount Ararat, and Nehumkeag Pond member…. The Mount Ararat Member consist of 2-10 cm alternating bands of light gray quartz-plagioclase-biotite granofels or gneiss, and dark gray biotite-rich amphibolite with extensive intervals of the light gray gneiss (Hussey 1981. p. 4)….Brookins and Hussey interpret Rb/Sr whole rock ages of the cushing formation to reflect the age of volcanic activity, and not of a metamorphic event (Hussey, 1981. p. 5)

The Lanchance quarry is located within these series of rocks. At the quarry most of the mineral structures are uniform- absent of adulteress materials-not to imply that other minerals are not present. Fractionation is minimal; the body of the pluton protected movement within the core of the pegmatite. Little re-melting took place after emplacement, keeping the minerals intact today as they were upon emplacement. Unlike the other structures visited.

Topsham: (see figure C) The fisher quarry lies within Mount Ararat Member, dated Cambrian --Ordovician, and is part of the Cushing formation also (Geologic Map. Maine, 1985). “In contrast to the majority of Topsham pegmatites, the Fisher quarry is undoubtedly the most fractionated pegmatite in the area…the area lies just west of the Norumbega fault” (Francis, Wise, 1992. p.85) where great pressure had built up. The Fisher Quarry " is one of the few places in the area to contain replacement units and pocket" (Francis, Wise, 1992. p.85). The facts presented here will build a theory of why Optical quartz is more prevalent in one area then another.

Alburn: The Lewiston and Auburn area is part of the Sangerville formation. Age: Late Ordovician(?) to late Silurian (Hussy, 1981. p.8). This study will focus on where quartz was purchased Mount Apatite. The environment at Mount Apatite is consistent with granite

Figure C: Geologic Bedrock Map, Maine, 1985, Department of Conservation. Edited by: Philip H. Osberg University of Orono, Arthur M. Hussey Bowdoin College, Gary M, Boone, Syracuse University

pegmatite then fine-grained granite. It is comprised of mostly quartz, felspar, and mica and is surrounded by metamorphosed rock. Mount Apatite is noted for its fine green tourmaline and purple apatite that was discovered in 1901 in the famous Pulsifer Quarry.

Pegmatite

Magma, Arteries, Veins and Solidification: The pegmatite in the location listed above seems to range from simple pegmatites to very complex. The origin is still undetermined, but many theories have been adopted. Using the Bowen’s reaction series, as presented in the publication Understanding Earth By: Siever. Applying this theory would suggest that magma produced from the Sebago Batholith gave rise to this pegmatite. The theory further explains the dynamics of solution separation and at what temperature minerals solidify first and last within magma injected into the country rock. Magmatic differentiation pertains to the rise and fall of the parent magma and what stages crystallization (temperature) takes place. For our purposes we will explore this theory in-depth, because there is much to be understood how optical quartz solidifies. What conditions where present to enable the pegmatite’s to produce optical quartz?

The Brunswick, Thopsom, Alburn country rock area has been filled with magma that has been differentiated by the collection of other minerals, hence the solution needed to create the pegmatite’s. These other minerals were collected by the solidified magma passing through the country rock. While the liquid was traveling outward from the parent magma chamber [Sebago Batholith] carrying minerals away and mixing with country rock creating a new magma solution composition. Meanwhile this process was depleting the parent magma solution [see figure B]. “As the process continued, both melt and crystals gradually became richer in sodium and poorer in calcium” (Siever. 1997. p.87). The calcium rich magma was transported to the pegmatite chambers. With the parent magma solidifying, the magma injections slowed into the country rock as it cooled. Eventually flowage of magma from the parent magma was blocked off [see figure D] and mineral separation began in the pegmatite chambers that surrounded the Sebago Batholith. However with the exception of the LaChance Quarry most area pegmatities experienced later intrusions. These later intrusions introduced great pressure which partially re-melted metamorphic rock as the injection filled cracks and fissures. The Thopsom area has a number of granite quarries, which would indicate large intrusions. [discussed later in this study, mineral seperation]

The evidence brought forth from the field studies of these areas has revealed that within the complex pegmatite systems, rare earth elements are present. The presents of rare mineral crystals such as albite, tourmaline, apatite, and garnet, in these areas, are consistent with mineral separation that was interrupted by later intrusions. Another relevant aspect of this theory is that cooling must have took place over thousands of years. As the magma cooled, taking a plastic form, pressure and solution moving into the parent magma then reheated the chamber and its arteries. The magma squeezing outward into the pegmatite chambers introduced new elements that produced impurities that adulterated the mineral structures already in place. The pressure of this later intrusion contributed to the fractionation and some re-melting took place. Areas in the Brunswick
area did not show evidence of these later intrusions. Leading to the notion that pressure and adulteress mineral was not a key factor in the development of the optical quartz. This is not to say that rare earth elements are not present here, because they are. The theory being developed here is, the pegmatite chamber located in Brunswick [LaChance quarry] had one injection of magma that cooled over a very long time.

Pegmatite Core Dynamics: First lets explain further the dynamics of core solution within pegmatite. “Not unlike the parent chamber, there is a core, where the solution cools last”(Doyle, 2000). Normally these solutions are made up of quartz. The diagram in figure D explains this dynamic process, the LaChance quarry. Figure E shows the contrast to figure D, Figure E Mount Apatite [Auburn Maine.] and Fisher Quarry [Thopsom Maine.]. Although the dynamics may differ from location to location, the models shown in figure D and E are to be used as a general conception of core dynamics.

In diagrams E, Mount Apatite site, shows the creation of this pegmatite. The construction happens by successions of injection into the surrounding country rock. These later injections were once again forced throughout the country rock. The pressure, new solution and heat from this force began the process of alteration to the already harden pegmatite zone. The results are that the existing minerals in place have been adulterated by these injections. The forces mention here have many variables in how the minerals are altered. The first being that more oxygen is supplied to the pegmatite, this can accelerate cooling. Another element of accelerated cooling is that the pegmatite had already begun to harden, hence the new injection was met by lower temperature rock. Rapid cooling produces impurities such as oxygen bubbles. The abundance of the oxygen bubbles found at Mount Apatite is relatively high as is true for Thopsom area pegmatite [Fisher Quarry]. Optical quartz exists in these areas on a much lower scale then at the LaChance quarry. The reason for this is because the later injections did not reach the center of the quartz core within the pegmatite. And this is where most of the optical quartz is found. The reason for relatively small amounts of optical quartz came from areas is because part of the quartz core did not become adulterated.

In contrast to these events, the LaChance quarry shows no evidence of this adulteress material. In fact it shows evidence that the pegmatite in this area remained stable after the primary injection. A large area outcrops of granite, surrounds and protects the area pegmatite (see figure F, p.14). This surrounding granite may in fact be the parent solution that produced this particular pegmatite, or it’s, a main artery from the Sebago Batholith that became block. A later injection found new routes that produced the chamber of magma. In any event one could surmise that this artery was block early in the development of the Sebago Batholith (see figure D). If this is so then the depletion of minerals that produced the pegmatite may have came from this blocked magma chamber.

Note: Thopsom, and Alburn pegmatities are surrounded by metamorphosed rock. The Thopsom area has a number of granite quarries that produce large enough quartz veins that were prospected for it glassy quartz and gem Beryl.

Having eliminated pressure and adulteress material as an agent in production of optical quartz at the LaChance quarry, leaves us to peruse formation of optical quartz on a molecular and composition level. To get a better understanding of quartz and its properties, an outline is provided below.

Overview of Quartz and its Properties : Quartz SiO₂

Amethyst Galleries, Inc (provides the outline below, 2000).

THE MINERAL QUARTZ

· Chemistry: SiO2 , Silicon dioxide

· Class: Silicates

· Subclass: Tectosilicates

· Group: Quartz

· Uses: silica for glass, electrical components, optical lenses, abrasives,

gemstones, ornamental stone, building stone, etc.

· Additional variety specimens include:

· Amethyst is the purple gemstone variety.

· Citrine is a yellow to orange gemstone variety that is rare in nature but is

often created by heating Amethyst.

· Milky Quartz is the cloudy white variety.

· Rock crystal is the clear variety that is also used as a gemstone.

· Rose quartz is a pink to reddish pink variety.

· Smoky quartz is the brown to gray variety.

PHYSICAL CHARACTERISTICS:

· Color is as variable as the spectrum, but clear quartz is by far the most common

color followed by white or cloudy (milky quartz). Purple (Amethyst), pink

(Rose Quartz), gray or brown to black (Smoky Quartz) are also common.

Cryptocrystalline varieties can be multicolored.

· Luster is glassy to vitreous as crystals, while cryptocrystalline forms are usually

waxy to dull but can be vitreous.

· Transparency crystals are transparent to translucent, cryptocrystalline forms can

be transparent, translucent or opaque.

· Crystal System is trigonal; 32

· Crystal Habits are again widely variable but the most common habit is

hexagonal prisms terminated with a six sided pyramid (actually two

rhombohedrons). Three of the six sides of the pyramid may dominate

causing the pyramid to be or look three sided. Left and right-handed crystals

are possible and identifiable only if minor trigonal pyramidal faces are

present. Druse forms (crystal lined rock with just the pyramids showing) are

also common. Massive forms can be just about any type but common forms

include botryoidal, globular, stalactitic, crusts of agate such as lining the

interior of a geode.

· Cleavage is not present.

· Fracture is conchoidal.

· Hardness is 7, less in cryptocrystalline forms.

· Specific Gravity is 2.65 or less if cryptocrystalline. (average)

· Streak is white.

--------------------------------------------------------------------------------------------------

· Other Characteristics: striations on prism faces run perpendicular to C axis,

piezoelectric (see tourmaline) and index of refraction is 1.55.

· Associated Minerals: Are numerous and varied but here are some of the more classic associations of quartz (although any list of associated minerals of quartz is only a partial list): amazonite a variety of microcline, tourmalines especially elbaite, wolframite, pyrite, rutile, zeolites, fluorite, calcite, gold, muscovite, topaz, beryl, hematite and spodumene.

· Best Field Indicators are first the fact that it is very common (always assume transparent clear crystals may be quartz), crystal habit, hardness, striations, lack of cleavage and good conchoidal fracture.

Pauling Rule: Using the theories proposed in the section on pegmatite of this study, with adulteress material being absent, brings us to a level of purity in the quartz. Pauling rule as discussed in the book, Physical Geology, implies the perfect balance of ions within silica. Pauling rule also discusses the precise formulation of two-consideration eletroneutrality and geometric packing. Stable crystal structure result from the interplay of these two considerations. Optical quartz is considered stable because of its eletroneutrality and Model By: Bradstreet

geometric packing. The arrangement of atoms is noted as four oxygen ions around one silica ion. source for Paulings rule (Deffeyes, Hargraves, Judson, Physical Geology 1976. p.44).

Ionization Potential

When electrons are either removed or gained by an atom there is a transfer of energy. The amount of energy required to remove an electron is called the ionization potential. The version of the periodic table shown below gives value of the first ionization potential. Note that elements with high ionization potential do not like to give up electrons, while those with low ionization potential can give up electrons more readily and tend to become cations. We can make the following observations:

Group IV elements tend to lose 4 electrons to

become +4 ions (i.e. C⁺⁴, Si⁺⁴, Ge⁺⁴). But Pb,

usually only loses 2 electrons to become Pb⁺².
Model shows the silica losing its oxygen then becomes +4 ion ( Model by: Bradstreet)

· The Noble gases all have very high first ionization potentials, indicating that their electronic structure is stable. A glance at the periodic table showing filling shells (above) indicates that the Noble Gases all have in common completely filled p - orbitals. It is because these sub-orbital shells are full that these elements do not readily become ions and do not easily combine with other elements to become compounds.

Crystal Chemistry provided By: Prof. Stephen A. Nelson, Tulane University, Geology 211, Mineralogy, http://www.tulane.edu/~sanelson/geol211/index.html#Links, last modified on 10/7/99

Ionization Potential, is not to be used for commercial publication.

How did these conditions reach the optimum environment for optical quartz? Upon examination of optical quartz in the LaChance quarry, using the ionization potential within the bounds of crystal chemistry, we can assume the equilibrium of the quartz core was at its optimum level, upon solidification. Using the ionization table above, one can observe that Silica (Si) has a high resistance in giving up its electrons, which only further contributed to the equilibrium of the core in the Lachance quarry. In contrast the Thopsom, and Alburn area pegmatite’s revealed Fractionation and replacement minerals. The Fractionation produced a very unstable environment and the forces where great enough that the atoms could not arrange together to form any kind of core. The observations made in this area are that these rocks underwent great pressure; hence the evidence of later intrusions is clear. It really comes down to the fact that adulteress material is the chief component in making these surrounding pegmatites impure. In contrast to this negativity, these impurities (later magma injections) were the building blocks for rare earth elements.

More discussion on solidification: Remembering the process of solidification took place over a temperature range that spanned hundreds or perhaps thousands of years. It is hard to conceive that this rock formation remained stable, during all the volcanism of this period. However if the proposed theory is correct what did remain stable is the constant balance [uninterrupted by later injections] of solutions. Fractionalization occurred within this area due to tremors, earthquakes, and the shifting of near by rock bodies that had later injection. The pressure of these later injections then squeezed the already hardened rock creating fractionalization within the rock structure. With this knowledge it is easy to understand the reason why large bodies of uninterrupted quartzes are sparse.

Past studies: The studies presented by the Schenectady Museum Archives, revealed that Elihu Thomsom achievements while building the refractive mirrors was a stepping stone in quartz history. His work brought forth many new question and research into the area of silica. The work was well noted for the annealing process of fused silica. He also discovered Pyrex during the process.

“During and after World War II, the Army Signal Corp sponsored and subsidized a comprehensive program to develop domestically grown quartz. The program was successful and resulted in the commercial production of cultured grown quartz in 1958” (United States Bureau of Mines, 1975. p. 881). This was the development of the autoclave and “by 1975 there were 475 operating in the United States” (United States Bureau of Mines, 1975. p. 881). The autoclave gave rise to the production of reliable quartz that could be processed much quicker and have a high-grade value.

In today’s technology silica has become an intricate part of our society. Changing the way the world communicates, as with remarkable discovery in medicine. Communication has now expanded through the use of the computer (silicon chips), this vast network of chips per-say has ensured the stability of communication.

The aid of the computer has touched almost every industry on the planet. Uses include communication, information management, molecular, electrical, aerodynamics, and quantum physics simulation…etc. Using simulation as an aid to science has enabled predictability within research, further ensuring the safety of the design phase; saving lives and money.

One remarkable discovery worth noting is the restoration of eye site by silicon chips.

In landmark surgeries at the University of Illinois at Chicago Medical Center on June 28, the first artificial retinas made from silicon chips were implanted in the eyes of two blind patients who have lost almost all their vision because of retinal disease. Both patients were released from the hospital the following morning. Preliminary tests determined that no complications had occurred. A third patient received an implant June 29 at Central DuPage Hospital, in Winfield, Illinois. (ScienceDaily Magazine, 2000).

The list of uses for silicon within our society is vast and has made remarkable changes within the evolution of man. With the knowledge behind us in regards to silicon one can only imagine the future! If it had not been for the first pioneers investigating into the rock around us we may not have had the ability and luxury of today’s technologies.

Summary

Tying all the data together: Many that study this area of pegmatites have different theories and conception in respect to the Sebago Batholith and its surrounding pegmatite. The field of geology is highly speculative, but there are indisputable mechanism and forces that science has unraveled.

The event, the Sebago Batholith, set in motion the mechanism of creation for its surrounding pegmatite. It is conceivable that separate plutons where injected into the country rock that surrounds the Sebao Batholith. These surrounding plutons are relatively the same in composition as the Sebago Batholith, but the pegmatites that formed within these granites are somewhat different. The different composition can be contributed to many variables. These variables are: distance the magma traveled, different rock formation the magma traveled through, time cooling, rapid cooling agents, pressure, later injections of magma, and mineral compositional changes; that these magma underwent while traveling.

Reiterating the key issues: Many agree that magma emanating from the core can form numerous chambers that spread of many kilometers of country rock. Also many agree the wall rock is re melted adding compositional changes to the solidified magma.

This study has concerned itself with many aspects of geology. Its focus is the occurrence of optical quartz at LaChance quarry. Quartz, SiO2, (2 parts oxygen and one part silica) that is found at the LaChance quarry is optimally balance. The eletroneutrality and geometric packing are necessary components when determining the optical value of quartz.

Conclusion of the study: It is certain that optical quartz is present in Maine’s pegmatite. What conditions made this possible is what this study has tried to unravel. It would be presumptuous to say that one contributing fact was the cause of theses conditions. Geoscience and Geochemistry has enabled us to narrow the agents of creation.

These agents are:

· Re-injections of magma into the smaller chambers surrounding the Sebago Batholith, which supplied the chambers with more oxygen, upon cooling

· Magma becoming adulterated as it forced its way through the country rock

• Temperature fluctuation vs. temperature stability

To obtain optical quartz the oxygen within silica needs to have a perfect balance one-part silica and 2-parts oxygen. It is when quartz is off balance, that quartz becomes milky having non-optical properties. Silica that becomes adulterated either changes completely to another mineral or it becomes colored, depending on the agent imposed on the silica. If quartz cools at a slow rate, uninterrupted it is more likely that the quartz will remain stable then if it cools at a rapid rate. This is because rapid cooling is generally produced by other elements interacting with the silica, hence adulterated the silica.

One could conclude that the quartz found at the Lachance quarry in Brunswick Maine was un-adulterated and remained stable until complete solidification could take place.

Bibliography and Work Cited

Below is the Information that assisted in this study

Behn, Mark D, Eusden, Dykstra J. JR., and Notte, John III A, A Three-Dimensional

Gravity Model of the Southern Contact of the Sebago Pluton. Maine
Department of Geology, Bates College, Lewiston

http://www-geodyn.mit.edu/mark/CJES_1998.html

This web site posting shows the gravitational settling of the Sebago Pluton. It also

show the orientation of the Pluton itself

Cameron, Eugene N, 1942-45, Pegmatite Investigations 1942-1945 New

England Geological Survey.; Professional Paper 255.

United States Government Printing Office, Washington :

The report is based on work done jointly by: Eugene N. Cameron, David M.

Larrabee, Andrew H. McNair, James J. Page, Glenn W. Stewart, and Vincent E.

Shainin

Cox, Keith, Gordon, Bell D. J, and Pankhust R, J, 1979, The Interpretation Of Igneous

Rocks. Ed. George Allen & UNWIN LTD, Printed: William Clowes & Sons

Limited,

The reference supplies a general knowledge of igneous rocks, has been used here to

substantiate collaborational view of igneous rocks.

Deffeyes, Kenneth, Hargraves Robert, and Judson, Sheldon. Physical Geology. 1976. ED. Pretince-Hall, Inc New York, Princeton University

This book is an introduction to Physical Geology. It has been written for the use of both majors and non-majors, in a one semester or one-term at the college level

Doyle, Robert, 2000, Professor of Geology at University of Maine, Augusta, Previously server has Maine State Geologist,

Francis, Carl A, and Wise, Michael, A, 1992, Distrubution, Classification and Geological Setting of Granite Pegmatities in Maine; Notheast Geology, Vol. 14 No. 2&3. (82-93 p)

Michael Wise Department of Mineral Science, Smithsonian institution washington DC USA 20560 and Carl Francis Harvard Mineraology Museum Cambrige, MA 02138

Geologic, Bedrock Map Maine. 1985, Department of Conservation. edited, Philip H. Osberg University of Orono, Arthur M. Hussey Bowdoin College, Gary M, Boone, Syracuse University

Hussey Arthur M, II, 1981, Bedrock Geology of Lower Androscoggin Valley – Casco Bay Area; Maine Geological Survey. Open File #No. 81-29

This report is a preliminary and has not been edited or reviewed for conformity with Maine Geological Survey standards

Hussey Arthur M, II, 1983, Bedrock Geology of Lewiston 15-minute Quadrangle, Maine; Maine Geological Survey, Open File #No. 81-29

Lachance, Geoffrey. July 2000, Personal Interview. 16 July. 2000, owner of LaChance

Quarry

The Mineral Gallery: ,1998 by Terran Technologies, Inc. All rights reserved.

http://mineral.galleries.com:/minerals/SILICATE/QUARTZ/quartz.htm#p

Note: Unless otherwise noted, all mineral descriptions and images, plus the related descriptions on this server is the property of Amethyst Galleries, Inc., and may not be copied for commercial purposes. Permission to copy descriptions and images is granted for personal and educational use only. All such copies must include this copyright notice and explicit references to the URL http://mineral.galleries.com/.

All programs and data structures are Copyright © 1995,1996,1997,1998

Laverdiere, Gary, July 2000, Personal Interview: 20 + years of pegmatite investigation

Maine Geological Survey, 1957 Maine Pegmatite Mines And Prospects & Associated

Minerals. Mineral Resources Index No. 1. State Geologist: John Rand,

Department of Development of Industry and Commerce

Präzisions Glas & Optik. Quartzglass Components

http://www.pgo-online.com/intlframes/uebersichtset.html.

Date access, July 2000

This online documentation gives a brief overview about standard products and

standard optical glass types.

Press,Frank Siever, Raymond, 1997, Understanding Earth / Frank Press, Carneie

Institution of Washington Raymond Siever Harvard university -2^nd ed. First

printing, 1997, by: W. H. Freeman and Company

ScienceDaily Magazine, 2000, (Source: University Of Illinois At Chicago

(http://www.uic.edu) Date: Posted 7/3/2000)

Http://www.sciencedaily.com/releases/2000/07/000703101426.htm

In landmark surgeries at the University of Illinois at Chicago Medical Center

on June 28,

Thomsom, Elihu. 1931, GE Scientist and Engineer, MIT Graduate: Served on Board of

Directors. Schenectady Museum Archives, Archivist: Chris Hunter, GE Historical

Research Department

Tucker, Robert, D, and Marvinney, Robert, G, 1989, Studies in Maine Geology

Ingeous and Metamorphic Geology. Vol #3. Department of Conservation

United States, Bureau of Mines, 1975, Mineral Facts and Problems. Ed. Staff, Bureau of

Mines. Washington: The Bureau: for sale by the Supt. Of Docs. U.S. Govt. Print

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1,266 P.: 203 diagrs cm (bulletin – bureau of mines: 667 ISSN 0082-9129) 1.

Mines and mineral resources- United States 2. Mineral Industries- United States I.

Title: (series: United States. Bureau Of Mines. Bulletin – bureau of Mines; 667)

This reference can be found at Bates College Library, in Brunswick Maine where

a extenxise collection of Bureau of Mines collection is housed