81. Fort Irwin Geology Stuff Other interesting geology information. most distinctive shapes because it has bigcrystals that separate where water can carry on its breakdown of the minerals. http://wrgis.wr.usgs.gov/docs/geologic/Fort.Irwin.ES.web/FIotherinfo.html

and U.S. Army Earth Science Applications, National Training Center, Fort Irwin Other interesting geology information Tors and desert erosion As rocks at and just beneath the desert surface are subjected to the physical wear of wind and rain, and to chemical breakdown from water and acids produced from plants, they weather to form interesting erosional shapes. Granite (shown in reds and greens on the geologic map ) makes some of the most distinctive shapes because it has big crystals that separate from one another readily. As granite erodes, much chemical action typically is focused along planes of fractures, or joints, where water can carry on its breakdown of the minerals. Big cubes of granite result, which then undergo rounding of their corners. The final result is round, boulder-like masses of granite. These often appear in big stacks that look from a distance to be pinnacles of gigantic boulders. Geologists call these pinnacles 'tors'. Outstanding examples can be seen at Fort Irwin, as well as in many parts of the Mojave Desert; some of the best are in Joshua Tree National Park and Mojave National Preserve. Because the minerals that erode from granite are big and resistant to being broken down to smaller sizes, they form coarse sand sheets on the granite and around tors. After millions of years of erosion, masses of granite commonly take on a gently domed shape several miles across, with tors protruding from the gentle dome surface. These features are referred to as 'desert domes'. An excellent example is traversed by the main highway into Fort Irwin along the first 5 miles or so within the boundary of the base.

82. Research Topics: Science - Geology Rock Hunter's Guide, Russell P. MacFall, 247. The World's Finest Mineralsand crystals, Peter Bancroft, 176. geology, Frank HT Rhodes, 160. http://www.bhil.com/~bhlibrary/RT/rt_sci_geo.html

Research Topics: Science - Geology Research Topics Research Topics: Science Research Topics: Science - Geology Title Author # of Pages American Gem Trails Richard M. Pearl Rocks and Minerals: A Guide for Collectors of the Eastern United States H. H. Nicolay and A. V. Stone How to Know the Minerals and Rocks - 46 Full Color Illustrations and 156 Drawings Richard M. Pearl Crystals and Crystal Growing Alan Holden and Phylis Singer Colorful Mineral Identifier Anthony C. Tennissen, Ph.D. Gems and Minerals in Color Rudolph Metz Rock Hunter's Guide Russell P. MacFall The World's Finest Minerals and Crystals Peter Bancroft Geology Frank H. T. Rhodes Geology: Our Changing Earth Through the Ages Jerome Wyckoff

83. Maine Geology - Mineral Collecting The Maine State Museum in Augusta contains an exhibit of superb tourmalines and othercrystals and gems Entire issue on the minerals and geology of Maine. http://www.state.me.us/doc/nrimc/pubedinf/factsht/economic/mincolec.htm

MAINE DEPARTMENT OF CONSERVATION Maine Geological Survey Mineral Collecting Maine has an excellent reputation among "rockhounds" for the variety and quality of mineral specimens found within its borders. Hundreds of people explore the state each year in search of crystals, semiprecious gems, gold, and other minerals. The novice is practically assured of finding something of interest at Maine's collecting sites, while a large assortment of rare minerals await the advanced collector. Mineral collecting is an inexpensive hobby that can be enjoyed by all age groups, and offers the fringe benefits of outdoor recreation and the opportunity to learn about earth science. Many of the best minerals in Maine are found in an igneous rock called "pegmatite", which is a very coarse-grained granite. Some pegmatites are enriched in uncommon minerals such as beryl, topaz, and colored tourmaline; they may also contain very rare species or large crystals of various minerals. Pegmatite veins are abundant in parts of Oxford, Androscoggin, and Sagadahoc Counties. Most of them were commercially worked for mica or feldspar, creating piles of waste rock ("dumps") where collectors search for specimens. Road cuts and natural outcrops of other rock types occasionally provide good mineral specimens. This is particularly true of coarse-grained metamorphic rocks produced by the deep burial and recrystallization of ancient marine sediments. Examples of metamorphic mineral occurrences include the kyanite and staurolite crystals in mica schist at Windham, garnet crystals in schist and calcium-rich rocks at numerous places, and vesuvianite crystals in Sanford.

84. Maine Geology - Maine's State Mineral, Tourmaline Tourmaline is one of the most attractive minerals occurring in Maine. Individual crystalsrange from opaque to transparent and may be single or multicolored. http://www.state.me.us/doc/nrimc/pubedinf/factsht/bedrock/stminral.htm

MAINE DEPARTMENT OF CONSERVATION Maine Geological Survey Tourmaline: Maine's State Mineral Tourmaline is one of the most attractive minerals occurring in Maine. It ranges in color from black or white to vibrant shades of red, green, and blue. The color of the best Maine specimens rivals that of tourmaline from world-famous localities in California, Brazil, and the Himalayas. Individual crystals range from opaque to transparent and may be single or multi-colored. There is even a "watermelon" variety with a green outer layer surrounding a pink core. Transparent crystals that are clear enough to yield faceted gemstones are highly prized, while lesser grades of this durable mineral are tumble-polished for use in various kinds of jewelry. Well-formed tourmaline crystals in their natural state are also sought by mineral collectors. TOURMALINE DISCOVERIES IN MAINE The first major tourmaline discovery in Maine occurred in 1820 at Mount Mica in Paris. The famous story of the discovery by two boys exploring the local countryside was related by Augustus Hamlin in his 1895 book entitled "The History of Mount Mica". A quarry that was opened at the site has intermittently produced gem tourmaline and other interesting minerals up to the present day. The Hamlin Necklace, containing fine tourmalines of various colors from this quarry, can be seen in the Harvard University Mineralogical Museum. Many other tourmaline deposits have been found in Maine over the years. Sharp crystals of black tourmaline are widespread in pegmatites of Oxford, Androscoggin, Sagadahoc, and Cumberland Counties. The colored crystals occur mainly in Oxford County and the Auburn-Poland area. It is curious that the best gem-producing localities lie on a straight line extending southeastward through this part of the state. In 1972 a spectacular series of large tourmaline pockets was opened at the Dunton Mine in Newry. Hundreds of pounds of red and green crystals were found, including the "Jolly Green Giant", a 10-inch crystal now in the collection of the National Museum of Natural History in Washington, D.C. The State of Maine tourmaline necklace was designed using Newry gems and presented to the State in 1975 by the Maine Retail Jewelers Association. (The chain of this necklace was made from gold nuggets panned from the Swift River in Byron.)

85. UWRF Geology - Dr. Bill Cordua brittle, tenaceous and dented minerals minerals of the Bronk Minnesota Twin CrystalsMoonstone An exsolution to its mystery geology and mineralogy of the http://www.uwrf.edu/~wc01/leaverite.html

LEAVERITE NEWS ARTICLES BY WILLIAM S. CORDUA These are one-page popular science articles written on mineralogical and geological subjects for the Leaverite News newsletter of the St. Croix Rockhounds. They have been reprinted by other newsletters. Some have won regional and national awards through the Midwest Federation and American Federation. Copies of those not linked yet from this page can be obtained from me. E-MAIL ** indicates award-winning articles Determining the source of gem emeralds Fluorescent Minerals of Wisconsin Feeling Minerals Dense as a rock ... Floating Copper The Great St. Croix Meteorite Hunt 1997 Wisconsin Wavellite **Minerals from Kidney Stones Agates - Full of Fiber Rust Minerals ... Mellen Black Granite A mineral from giant red suns A Lake Full of Lead Blue, Blue, My Quartz is Blue Why do pyrite crystals show different faces Moganite - a common mineral with a disapproved name Book review : Gene LaBerge, Geology of Lake Superior Epidote Hibbingite - swimming pool mineral A new place to look for diamonds Hourglass gypsum Wisconsin talc Geology and the Growth of Downtown Stillwater Moon minerals found on earth Moonmilk The fire of opal 1992 A St. Croix Meteorite

86. MGS On-Line List Of Publications: Online Bookstore Earth An Introduction to Physical geology by Richard M A Field Guide to Rocks andMinerals (Peterson Field crystals and Crystal Growing by Alan Holden, Phylis http://www.mgs.md.gov/esic/publications/books.html

Educational Publications Earth Science Books Online contact: Jim Reger (jreger@mgs.md.gov) Looking for a good book? Let us suggest some earth science publications through Amazon.com . Click on a title to find out about a book or to order it from Amazon.com. If you want to look for other titles, type in a keyword in the search box to the right. If you would like to suggest a book to be added to this list please email the information to Bob Conkwright ( tbird@mgs.md.gov Search: Books Keywords: General Geology Maryland's Geology by Martin F., Jr. Schmidt (1993) Roadside Geology of Virginia (Roadside Geology Series) by Keith Frye, David Alt (Editor), Donald W. Hyndman (Editor) (1986) Earth : An Introduction to Physical Geology by Richard M. Busch, et al Annals of the Former World by John A. McPhee (1989) Dictionary of Geological Terms by Robert L. Bates, Julia A. Jackson (Editor) (1984) Earth Story : The Shaping of Our World by Simon Lamb, David Sington (1998) A Field Manual for the Amateur Geologist : Tools and Activities for Exploring Our by Alan M. Cvancara (1995)

87. GEY 101 - Introductory Geology: Exploring Planet Earth GEY 101 Introductory geology Exploring Planet Earth Igneous Olivine and Calcium-Plagioclasecrystals form first. These minerals are rich in Magnesium, Iron http://geoscience.unlv.edu/pub/snelson/GEY101/Igneous.html

GEY 101 - Introductory Geology: Exploring Planet Earth Igneous Rocks ROCKS There are three kinds of rocks, that are defined on the basis of how they formed. Igneous Rocks are formed from the solidification of molten rock or magma. Sedimentary Rocks form through when materials at the earth's surface (sediments) are buried and hardened (lithified). Metamorphic Rocks are formed when older rocks are changed by heat and pressure without being melted. Magma Parent material of igneous rocks Forms from partial melting of rocks inside the Earth Magme that reaches the surface is called lava IGNEOUS ROCKS There are two types of igneous rocks, that are differentiated by how they occur. Intrusive Rocks form when magma solidifies beneath the earth's surface Extrusive Rocks form when magma solidifies on the earth's surface as lava (at volcanoes). Components of Magma Melt liquid portion that is composed of mobile ions Solids silicate minerals that have already cyrstallized from the melt Volatiles gases which are dissolved in the melt. This includes water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) Crystallization Cooling of magma results in the systematic arrangement of ions into orderly patterns The silicate minerals resulting from crystallization form in a predictable order texture in igneous rocks is determined by the size and arrangment of mineral grains Igneous rocks are typically classified by texture mineral composition Texture describes the overall appearance of a rock based on the size, shape, and arrangement of interlocking minerals.

88. Geology 1010 – Matter And Minerals geology 1010 – Matter and minerals. charged with water 2) in voids where crystalsgrow toward Cleavage the tendancy of minerals to break along planes of weak http://www.colorado.edu/GeolSci/courses/GEOL1010-4/Minerals.htm

Geology 1010 – Matter and Minerals Minerals : a natural inorganic solid with a unique chemical composition and a regular internal structure. Rocks : a consolidated mixture of minerals. Crystal : materials with an orderly arrangement of atoms. Solid typically bounded by smooth faces that reflect a regular an repeated arrangement of atoms. Atoms – small aggregates of particles that are the building blocks of all matter. Atoms are composed of smaller particles including protons, neutron, and electrons Elements – substances that cannot be broken down to simpler substances by ordinary chemical or physical means. Elements reflect different kinds of atoms, differentiated by the number of protons they contain. 8 most abundant elements in the Earth’s crust: see Table 2.3 in Tarbuck and Lutgens (1999): O, Si, Al, Fe, Ca, Na, K, Mg Atoms are bonded by various ways of attraction: covalent bonds, ionic bonds, metallic bonds Bonded atoms form compounds Crystals represent the regular stacking of atoms, with systems and 32 classes of crystal forms representing all the different way atoms of different diameters can be stacked. Crystals form from the solidification of materials in a cooling or evaporating liquid.

89. EDU2 : Level 4 crystals jp mineralogy; Clay Mineralogy and Geochemistry; Claylab; Commercial MineralNames; Earth Materialsminerals; GEOL4550/6550 Clay Mineralogy; geology 3010 http://www.my-edu2.com/EDU/geogra6.htm

EDU2 :GEOLOGY - MINERALOGY ABCentral Search Helpers Submit a Link ... MINERAL MEASUREMENT *GEMOLOGY* 1a ganoksin.com - the gem and jewelry world's foremost information resource on the internet. Amber Home Amber homepage Amethyst Galleries' Mineral Gallery ... Zircons Are Forever *GEOCHEMISTRY* GEOCHEMISTRY : TITLE *MINERAL-FOSSIL* EDUARDO JAWERBAUM:and fossils and minerals Jan's Mineralien- und Fossilien-Seiten Kato's Mineral Fossil Collection Minerals Management Service - Gulf of Mexico Region *MINERALOGY REGIONAL* A Virginia Rockhounder Brazilian Minerals Crystal Caves: Atherton - North Queensland - Australia. Dendritic Dolimite:in saskatchewan ... minerals of scotland *MINERALS* 296-492 MINERALOGY-PETROLOGY ATHENA: MINERALOGY; Pierre Perroud Applied Turbidite Research Atlas of Rocks, Minerals, and Textures ... Virtual Atlas of Opaque and Ore Minerals *MINERAL MEASUREMENT* 1. Testing Hardness of a Mineral Dave Waters' Home Page:and thermobarometry ERSC 2P22:optical mineralogy Generalized Thermobarometry ... UNB GEOLOGY 2142 Lecture/Lab Summaries:optical mineralogy Return to ABCentral

90. Introduction To Physical Geology Syllabus Granulite lack foliation, have large granular equant crystals. Metamorphic mineralsand metamorphic grade We've said that metamorphic grade is a continuum http://www.geol.umd.edu/~jmerck/geol100/lectures/22.html

Metamorphic rocks II Two things to understand about metamorphic rocks: Different protoliths will form different metamorphic rocks under the same conditions The same protolith will form different metamorphic rocks under different conditions of temperature and pressure. So, we have metamorphic rocks and we know how they form. Now how do we recognize them? Two general methods: Metamorphic textures visible in hand sample. Identity of metamorphic minerals Metamorphic textures Foliation : Parallel planes produced by differential stress. May assume any angle to original bedding, but forms perpendicular to direction of differential pressure. Foliation is more likely to form from protoliths rich in feldspars and clay minerals than in quartz-rich rocks. We recognize two grades: Slaty cleavage : Special case of foliation in which rock splits along foliation planes that look generally similar to bedding planes in shale. Schistosity : Foliation marked by visible platy minerals. Foliated rock classification criteria Intensity of foliation Size of crystals Degree to which segregated into light and dark bands Metamorphic grade.

91. Sedimentary, Metamorphic, Igneous Rock Types [Athro, Limited: Geology] Most of these minerals have a dark color. eruptions dump magma out into the air,water or inject it in little intrusions into cold rocks, crystals never have http://www.athro.com/earth_science/rocks.html

Athro, Limited Earth Science Rock Types The major Rock Types and how they form Igneous Rocks Basalt Granite Igneous rocks solidify from a liquid magma as it cools. They are described on two axies: 1) Rocks that are quartz rich ( felsic ) to magnesium rich ( mafic ) and 2) fast cooling (small crystals) to slow cooling (large crystals). When a magma cools rapidly, mineral crystals do not have time to grow very large. When a magma cools slowly crystals grow to several millimeters or more in size. Granite and basalt are opposites on these axies for the description of igneous rocks - granite is a slow cooled quartz rich rock, basalt a rapidly cooled mafic rock. Basaltic lava flow, Idaho Basalt is the stuff of the ocean floor. It comes from fresh upwellings from the mantle. Basalts are extrusive igneous rocks rich in minerals containing magnesium and other similar metallic atoms. Most of these minerals have a dark color. Basalts are thus dark in color. Basalt cools rapidly as volcanic eruptions dump magma out into the air, water or inject it in little intrusions into cold rocks, crystals never have chance to grow large. A magma with at basaltic composition that cooled slowly and had a chance to grow large mineral crystals would form an intrusive igneous rock that we would call a gabbro.

92. OnTheWeb.com: Minerals crystals minerals at www. bestcrystals. com Hundreds of crystals and mineralsfrom around the world, from $1 to grade A collector's pieces. http://www.ontheweb.com/s/minerals_3.html

OnTheWeb.com Network Sites OnTheWeb.com Fonts.OnTheWeb.com Images.OnTheWeb.com Shop.OnTheWeb.com Baby.OnTheWeb.com Books.OnTheWeb.com Cameras.OnTheWeb.com Dvds.OnTheWeb.com Electronics.OnTheWeb.com Garden.OnTheWeb.com Hardware.OnTheWeb.com Kitchen.OnTheWeb.com Magazines.OnTheWeb.com Music.OnTheWeb.com Office.OnTheWeb.com Software.OnTheWeb.com Tools.OnTheWeb.com Toys.OnTheWeb.com VideoGames.OnTheWeb.com Videos.OnTheWeb.com Coupons.OnTheWeb.com ReviewIndex.com CashGames.OnTheWeb.com FreeStuffSearch.com TotalFreeStuff.com Free.OnTheWeb.com YourName.OnTheWeb.com Top20Free.com Web Shop Fonts Images ... Home Search Results Web Categories: Auto Business Travel Computers ... eCommerce Pop Web Searches: Collectibles Gifts Apparel Jewelry ... Mortgages Featured Links: SEASILVER Amazing Liquid Mineral Supplement! Endorsed by Robert Barefoot Lowest Prices on Quality Minerals Juice Plus Whole Food Nutrition Low Carb Supplement ... ReviewIndex.com: minerals Search Again: Smithsonian Handbooks Chris Pellant Only Prescription for Nutritional Healing... Phyllis A., C.N.C.... Only Web Search Results: minerals (page 3) Sub Categories: Rocks Crystals Geology Gold ... The Ultimate In Liquid Nutrition. . Sea Energy!

93. The Mineral And Gemstone Kingdom: Home Explore the physical properties of a range of minerals. Guide also features advice on collecting and a special gemstone section. http://www.minerals.net/

Awards and Affiliations Troubleshooting Site Info Credits Awards and Affiliations Troubleshooting Site Info Credits ... Pedometers

94. ESU Geology Museum Earth Science Department, Division of Physical Sciences Emporia State University, Emporia, Kansas 66801Category Reference Education Kansas Emporia State University...... You can see a western Kansas Cretaceous mosasaur, a giant ground sloth,a mastodon tusk plus other displays in the ESU geology Museum. http://www.emporia.edu/earthsci/museum/museum.htm

95. Texas Minerals http://www.tmm.utexas.edu/npl/mineralogy/Texas_Minerals/

Non-vertebrate Paleontology Laboratory Just what Is a Mineral? The Collections The Science of Minerals Mineral Genesis ... Home Texas Geology and Minerals The Llano Uplift The oldest rocks exposed in Texas formed over a billion years ago when thick sequences of sediment were deposited in an ancient sea that bordered the North American craton. Approximately one billion years ago, the southern edge of this craton collided with another continent or an oceanic plate in an tectonic event that metamorphosed the sediments into gneisses and schists and partially melted more deeply buried rocks producing granitic magmas. The metamorphic and igneous rocks produced in this orogeny, the Packsaddle Schist, Lost Creek and Valley Spring Gneisses, Town Mountain and finer-grained granites, are now exposed in the Llano Uplift in central Texas. The ultramafic rocks and serpentinites that make up the Coal Creek igneous complex are though to represent the remnants of the island arc that collided with the North American craton. Terlingua , Texas is the site of one of the world's largest mercury deposits. At one time this mine produced approximately one forth of the mercury used in the United States. The mercury ore, cinnabar, occurs as powdery red veins in the layered limestones and volcanic lavas and tuffs in Brewster County. Liquid mercury also occurs in Terlingua. Industrial use of mercury declined when it became known just how toxic mercury was, and mining ceased at Terlingua in the 1970's.

96. Mineralogy Database Complete, upto-date, mineral database containing 4 281 mineral species descriptions. These data are linked to mineral tables by crystallography, chemical composition, physical and optical properties, Dana classification, Strunz classification, http://web.wt.net/~daba/Mineral

Mineralogy Database in HTML Format . Last update 10/20/99. This mineral database contains more than 5,000 web pages of mineral data. There are 4,102 individual mineral species descriptions with links. Visit the " What's New " section for details. The Mineralogy Database is moving to a new, permanent domain. Please make sure to bookmark the new location at http://webmineral.com Mineral data on individual species are linked to the following mineral table by crystallography, X-Ray powder diffraction, chemical composition, physical and optical properties, Dana's New classification, Strunz classification, and alphabetical listings of mineral species. I have also included links to other sources of mineral data available on the WWW. What is a Mineral ? Selected mineral definitions. Crystallography Mineral species by crystal system. New Java Crystal Models. X-Ray Powder Diffraction Mineral species by intensity and D spacing.(400 kb) Chemical Composition Mineral species by chemical elements selectable from a periodic table. New Dana Classification Mineral species by New Dana system.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

Page 5     81-96 of 96    Back | 1  | 2  | 3  | 4  | 5