Between vermiculite and montmorillonite which one expands faster and why?
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In general, the more clay in the soil, the higher the cation exchange capacity, the greater the rates of expansion (i.e. greater rates of saturation).\n\nMontmorillonite would expand quikcer because it has the highest cation exchange capacity of all the 2:1 lattice clays.  This higher cation exchange capacity allows for the clay minerals to bond quickly with water or with base cations present, therefore expanding quicker than vermiculite which has a lower cation exchange capacity. \n\nHowever, a vermiculite that is not saturated with base cations will expand quicker than a montmorillonite that is saturated with base cations.  If neither is saturated, the montmorillonite will expand quicker because of its greater cation exchange capacity.\n\nMontmorillonite clays mixed in with soil will be far more fertile than vermiculite mixed in with the soil.  However humus has an even higher cation exchange capacity than both montmorillonite and vermiculite.
717555
Well in fact it is about moisture content.  Un glazed clay pots most closely resemble soil.  The water is not contaminated and flows properly around the soil, also it is less expenseive and more traditional--glass wasn't commercailly feasible until the last couple hundred years--clay pots have been used since atleast 10000BC.
234816
I think the powder gets absorbed quicker.
642291
http://natres.psu.ac.th/Link/SoilCongress/bdd/symp9/1375-t.pdf
137292
You didn't really give me too many options with this one.  Increase or increase?  I think I'll have to go with "increase."\nSeriously, if a pipet is dirty, most likely it is contaminated with a salt compound, which would contribute to the density of something you were measuring out with the pipet.
745182
Silica weakly bonds to iteself (i.e. Hydrogen bonding) and it raises the viscosity.\n\nSo, low silica = runny lava, hi silica = thick lava
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WATER: water in touch with hot rock (or magma) changes into steam... the kind of eruption is named a phreatomagmatic eruption.\n\nSILICA: at greater percent of silica in magma, stronger eruption the volvano makes....
652500
Answer A) Small size & rocky surfaces
578445
the answer is that intrusive is formed inside the earth while extrusive is formed on the surface of the earth.
56158
Mohs' hardness scale is somewhat arbitrary.  Moh tried to find commonly available minerals that were about equally spaced in hardness.  Talc was arbitrarily assigned "1."\n\nAs one example of the inconsistency, diamond (Moh's 10) is about 10 times harder than corundum (Moh's 9).\n\nThere should be some minerals sites out there that allow you to list minerals in order of Moh's hardness.  There may also be some with Vicker's hardness for comparison.\n\nThe main advantage of Moh's hardness scale is its practicality for field use.\n\nA lot of the sheet silicates are very soft.  In the soft ones, the only forces holding the sheets together are van der Waal's forces, which are quite weak.\n\nClays are very soft.  The crystals are very small and only van der Waals forces act between them.  (They are also sheet silicates, but the sheets are held tightly together by cations.)
492924
i'm not exactly sure, but i would think that it would depend on the soil composition.  after all a fine clay has much different properties than a sandy or rocky soil
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Both of these will reduce the size of the ore, and both are used.  I think that they use crushing first.
36464
Check out this site: http://www.expanding-earth.org/\nSome scientists may dispute the notion that additional solid matter is created from solar energy by photosynthesis in plants and other living organisms, but they should consider coal beds that were formed from trees in the Carboniferous (~360 to ~290 Ma) but are now buried under deep overburden that accreted later. The huge fossilized tree trunks found in the Petrified National Forest near Holbrook in eastern Arizona are additional evidence of mass from solar energy. Also consider the massive deposits of limestone created by marine fauna (fish, coral, bivalves, microfossils, etc.) in earlier epochs and this growth continues today. Today, piles of leaves, wood chips and fallen trees are rapidly converted to soil by nematodes.  The whole question of added mass needs further research to more accurately determine the volume and sources.
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Robert has this correct.  Pumice is essentially volcanic glass with air bubbles, therefore pumice has the same hardness as obsidian, which is 6 - the same as the glass on your window.\n\nQuartz, with the same chemical composition SiO2, is harder (7) because it is crystalline.
69910
If you are asking what are the minerals that are most resistant to weathering, I can give you some help. How fast any particular mineral actually moves through the rock cycle is hard to answer, since it really depends on the setting.  In general the deeper a mineral forms (higher pressure and temperature) the more unstable it is at the surface. Quartz and muscovite are two of the more stable minerals. \n\nHere's some chemical weathering rates:\nMean lifetime of 1 mm or fresh rock (Nahon, 1991)\nRock Type................ Climate..................... Lifetime (years) \nAcid rocks...............tropical semi-arid.......... 65 to 200\n..................................tropical humid........................ 20 to 70\n..................................temperate humid........................ 41 to 250\n.................................. cold humid.................... 35 \nMetamorphic rocks..... temperate humid..........33 \nBasic rocks.................... temperate humid.........68\n..........................................tropical humid.............. 40
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The difference between a laccolith and an eroding laccolith is:\n\nA laccolith forms as an intrusive volcanic\nstructure. A laccolith is any of a type of igneous intrusion (or concordant pluton) that has been injected between two strata of a sedimentary bed. The pressure of the magma is high enough that the overlying strata are forced upward, giving the laccolith a dome or mushroom-like shape, the floor of which is usually horizontal.\n\nAn eroding laccolith has been\nexposed on Earth’s surface by the erosion\nof the layers of rock above it.
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Both are present in small amounts in soils and rocks.  Spillage from waste dumps can be a source also.