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Types of Porphyritic Rocks

Table of ContentsQuartz-porphyryFeldspar-porphyryLamprophyre Porphyry. — This name refers to the structure, which is formed of larger crystals set in a fine-grained or glassy ground-mass. The porphyritic structure may be plainly visible, the larger crystals being easily seen (phenocrysts), or it may require the microscope to bring it out. Porphyritic structure may appear in any igneous rock, but the true porphyries

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List Volcanic Rocks

Table of ContentsRhyoliteObsidianPitchstonePumiceBasalt or TrapAndesite We can list volcanic rocks that are formed at or near the surface by comparatively quick cooling of lava, cannot be classified without the aid of the microscope and chemical analysis, except roughly as light-colored and dark lavas, conveniently called rhyolite, and basalt or trap. Rhyolite Rhyolite is made of light-colored acid lava flows, often called

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Examples of Plutonic Rocks

Table of ContentsGranitePegmatiteApliteGraphic GraniteGreisenSyeniteNepheline-syeniteDioriteGabbroNoriteDiabasePeridotiteDunite or olivine-rockKimberlite or blue ground It is strongly recommended that these descriptions and examples of plutonic rocks be read with the specimens in hand, obtainable, as noted before, from the Geological Survey. Granite Granite is a coarse or medium- grained rock, composed of quartz, an acid feldspar or two of them (orthoclase, microcline, albite), and generally mica

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Volcanic Rock Formations

Table of ContentsVolcanoesLava FlowsVolcanic RocksRock MagmaGeysersRock intrusionsDikesSillsLaccolithsVolcanic NecksStocksBatholiths Volcanoes A volcano is the most striking evidence of a hot interior. There are about 250 active volcanoes at present, and about as many more that have been active in historic times. The cone shape of a volcano is due to its gradual building up by the ejection of material from the

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Small Gyratory Crushers

Table of ContentsGyratory Crusher Capacity TableTraylor Reduction CrusherGyratory Crusher Capacity Table The Allis-Chalmers (Type R) Small Gyratory Reduction Crusher is designed for large capacity, fine crushing and incorporates many improvements over other gyratory type crushers previously manufactured by this company. The most distinctive feature of the Type R Crusher is the built-in, oil filled hydraulic jack used for fast, positive change

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Stoichiometry of Excess Reagent Quantities

In this Example of Stoichiometry of Excess Reagent Quantities determination we show how do you determine how much of the excess reagent is left over & how to calculate how much more of the limiting reagent is needed to use up the excess reactant? Introduction: So far we have assumed that a given reactant is completely used up during the reaction. In reality

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How to do a Manual Titration

Those who do not know How to do a Manual Titration get their chance here with the step-by-step procedure. Rinse the inside of the Burette Rinse the burette with 2-3 mLs of standarized NaOH solution. Make sure all inside walls including the tip are rinsed. Fill the Burette Discard the rinse solution into the sink or a “waste” beaker. Close the stopcock,

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Effect of Copper Sulfate on Zinc Sphalerite Flotation

Table of ContentsOptimize Zinc Grade & RecoveryZinc Flotation As an example of the beneficial effect of copper sulfate in the activation of zinc sphalerite toward flotation, the series of results shown in Fig. 1 is of interest. These represent rougher tests on a sample of heavy pyritic ore. The particular sample in question contained about 5.6% zinc as marmatite; and was treated in

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How are Different Rock Types Formed

Table of ContentsDisposition of the SedimentOrigin of Sedimentary RocksRock ClassificationHow Conglomerate is FormedBrecciaSandstoneGraywackeArkoseShaleLimestone There are three great rock-making processes, namely: sedimentation movements of the melted rock or rock magma from within outwards metamorphism, or transformation of rocks by heat, pressure, and the influence of hot liquids and gases. These will now be discussed in order; and after the description of each

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Classes of Rocks

Table of ContentsArrangement of Sedimentary RocksFossilsLife Eras Three Classes of Rocks.—The rocks are divided into three great classes: Sedimentary rocks, made of fragments of older rocks more or less water worn or ground to powder, and then spread out and deposited in layers of gravel, sand, mud, etc., to be later consolidated by pressure and natural cementing. The material may

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Mechanical Weathering of Rocks

Table of ContentsWeathering ForcesMechanical ActionGeneral Effects of WeatheringGeneral Results of Weathering Weathering Forces Under this head are grouped a number of agencies that have their origin in the atmosphere, and which work not only on the surface but as far down as air and water, heat and cold, can penetrate. Because these forces work invisibly, they are apt to be

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Landforms Created by Glaciers

Table of ContentsOrigin of GlaciersMotion of GlaciersWork of GlaciersWork of Glacial StreamsThe Glacial PeriodPractical Results Origin of Glaciers In temperate and cold climates, and even in tropical countries, where there are very high mountains, the wastage of the snow by melting and evaporation may be less than the snowfall on the tops of the mountains; the snow, therefore, accumulates continually. In

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Types of Formations Caused by Erosion

Table of ContentsForces Causing ErosionChanges Caused by Running WaterRapids and WaterfallsNatural BridgesRiver TerracesUnderground Rivers, CavesLeveling EffectUnderground WaterErosion by WavesEffects of Waves on Rocky ShoresResultant Effects of Wave Action Forces Causing Erosion It is plain that ever since the crust of the earth became stable enough to allow water to stand, waves to form, rain to fall, and weather to act,

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Origin of the Earth

Table of ContentsThe EarthOrigin of the EarthStructure of the EarthWeight of the EarthSurface of the Earth The Earth As a preparation for the systematic study of rocks, it will be useful to look at the earth as a whole, inquiring into its origin, the changes that it has undergone and is still undergoing, and the nature and causes of the

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Mechanical Roasting in Silver-Lead Smelting

Table of ContentsRECOVERY OF OLD SPEISS BOTTOMSUSE OF THE BROWN-O’HARA FURNACESINTER SPEEDING UP BLAST-FURNACE WORKSteel Pipe Concrete Jacketed and Concrete LinedHoover and Wheeler at Chemical ExpositionAcetylene as a Precipitant for Cyanide Solutions What Colonel Dwight says regarding the treatment of oxidized ores holds true also of the silver-lead smelting operations in Utah. The ore sought for was such as would,

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Rocks and Mineral Identification Table

It is strongly recommended to the student of this book that he obtain specimens of rock, not labelled, and study their features with a view to naming them. The Table for Identification of Rocks will help in naming them. It may here be mentioned that the identification of rocks presents peculiar difficulties. Rocks are not definite substances; in some cases,

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Mineral Identification Tables

Table of ContentsHow to Use the Mineral Identification TablesMINERALS OF METALLIC LUSTERA.  Yellow or Yellowish ColorB. Red or Reddish ColorGray ColorWhite ColorBlack ColorMINERALS OF NON-METALLIC LUSTERA. Powder Distinctly ColoredPowder, White or Faintly Colored The various minerals have been described individually, so that any mineral specimen may be compared with a careful description of that mineral. The prospector’s task is to

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Sulphate Mineral Group

Table of ContentsBarite or BarytesCelestiteAnglesiteGypsumEpsomite or Epsom SaltMirabilite or Glauber’s SaltWolframite, or WolframScheelite The group of sulphates correspond to sulphuric acid, H2SO4. In the list of sulphate minerals, there are metals in place of the hydrogen of the acid; they are to be distinguished from sulphides, which contain no oxygen, but are made up of sulphur and metals. Barite or

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Phosphate Mineral Group

The Phosphate Mineral Group includes a number of the rarer minerals and apatite. Pitchblende or Uraninite is of Color, pitchy black, greenish, or brownish black; powder, brownish black, grayish, greenish; luster, dull and pitchy, sometimes slightly metallic. H = 5.5; G = 9 to 9.7; no cleavage; contains uranium, radium, etc. Found in pegmatite granite dikes, and also, in some cases,

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Mine Geology Sampling

Table of ContentsTHE OREBODIESSTANDARDIZATIONUNDERGROUND METHODSREPORTS OFFICE RECORDS The sampling and estimating of the orebodies in a mines have been made a part of the work of the geological department. The wisdom of this assignment is apparent, considering the organization of that department, the nature of its records, and the scope of its regular work. In the first place, the district is

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Mica Mineral Types

Table of ContentsMuscovitePhlogopiteBiotiteLepidolite Mica type minerals make a group of silicates of alumina, with potash, iron, magnesia; characterized by easy cleavage into thin, flexible, elastic sheets. Mica gives off water when strongly heated. Muscovite Muscovite, or white mica, (K,H) AlSiO4, is colorless, sometimes gray, brown, ruby, etc.; powder, white; luster, glassy or pearly; H = 2 to 2.5; G = 2.76

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Zirconium Minerals

Table of ContentsThoriteBerylAquamarine Zircon and Zirconium Minerals; ZrSiO4 are colorless, pale yellow, grayish, yellowish green, brownish yellow, reddish brown; powder, white or nearly so; luster, like diamond, or glassy; H = 7.5; G = 4.68 to 4.70; crystals, tetragonal; cleavage, imperfect; composition silicate of zirconia (ZrO2).—Found in igneous rocks of the acidic kind, for example, syenite, and especially in pegmatite dikes;

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Classification of Silicate Minerals

Table of ContentsFeldsparsHornblende VS AmphiboleTremoliteActinolitePyroxeneNepheline & NepheliteSodaliteLapis-lazuli or lazuríteZirconGarnetOlivine, Chrysolite or PeridotEpidote or PistaciteTopazTourmaline or SchorlCalamine or HemimorphiteStauroliteAndalusiteRhodoniteMicaChloriteSerpentineGarnieriteTalcSoapstone or steatiteKaolin or China ClayTitanite or Sphene The chemical name for the substance of quartz is silica; and any mineral that is composed in part of silica is a silicate. In the Classification of Silicate Minerals and the study of minerals and rocks, silica

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