Why do gnomes turn into stone?
469666
Thats impossible\nGnomes cant turn into stone
447024
It is chemical change. The material ( generally metal) gets oxidised when left in air and this is termed as rust.
1120157
The idea of the philosopher's stone was to transmute "base" metals into gold.  This was based on the alchemist's view of the structure of metals.  Alchemists believed that every metal was a form of gold; the ones that didn't look like gold (such as copper) were just impure forms of gold.  The role of the philosopher's stone was then to remove the "impurities" from the base metals.  There is no such thing as a philosopher's stone.
1066723
I'm quite sure it's A, extrusive rocks are exposed and cool very quickly.  Since they cool rapidly, crystals have no time to grow, and most crystals are smaller than a millimeter.  Obsidian, in fact, has no crystals at all and is a type of glass.  Intrusive rocks (such as granite) on the other hand, cool slowly (as they are insulated by the earth) and larger crystals form.  \n\nFor further information,\nhttp://www.geology.ufl.edu/Class_Notes/GLY2010_Fall_1996/summaries/intrus1.html\nhttp://www.nps.gov/brca/Geodetect/Rocks%20&%20Minerals/igneous.htm\n\nHope this is helpful.
572852
There are three major ways that rocks are formed. The first of these is from heat ie- igneous rocks. They are the volcanic rocks, among which are obsidian, and granite. Both obsidian and granite contain the same minerals but their different appearances are caused by differences in the speed of their cooling. Obsidian cooled very rapidly and has a glassy texture.  Granite cooled very slowly and the separate minerals crystallized into larger crystal. The three major minerals of granite and obsidian are quartz, feldspar, and mica, each cool at a different rate.\n\n\nGranite is an Intrusive rock=\nIgneous rock that cools and solidifies beneath the Earth’s surface\n\nObsidian is an Extrusive rock=\nIgneous rock that cools and solidifies at or very near earths surface eg- in a lava flow
780394
Yes it has something to do with acids.\n\nLimestone is CaCO3 deposits. If you look at the acid-base reaction between an acid and CaCO3 you can see that the carbonate ion favors being protonated and because of the fact that it's protonated state is very unstable it readily becomes water and CO2 gas. \n\n2 H+ + CO3 2- ---> H2CO3 ---> H2O + CO2\n\nThese two products of the reaction are very healthy for environments. However, since this reaction doesn't occur in areas of mostly granite, these bi-products aren't produced leading to the acid having a more detrimental affect on the surrounding environment.
82328
The rocks of the Giant's Causeway crystalized from molten rock or melted rock called magma.  This process makes igneous rocks. As the magma and rock cools, it loses heat and water, and as a result shrinks.   The shrinkage causes the polygon pattern which makes the Giant's Causeway famous, see photos at this web site: http://www.webvider.com/wwm/images/gb_u162.jpg\n\nGeologists call this pattern, when seen in igneous rocks, columnar joints.  Joints are the cracks which form during cooling.   Columnar joints are often seen in volcanic and shallow formed igneous rock such here in Northern Ireland, Iceland, and in North America,........all over the world where igneous rocks are found.
1056334
I watched that in a documentary! On the History channel or something... sorry I can't actually answer you're question I'm just letting you know that I like what you asked.  Maybe thought, maybe because of all the trade going on? Like people were selling the blue rocks (was it the blue ones? don't remember) they were selling them as jewellery. Actually! I have the answer! The blue rocks are in an ancient story that a blue rock would lead you closer to God - blue mountains - so when trades people came from wales to sell this little blue rock as a pendant they thought "ah ha" and went to mine it to bring it back (by boats) to their village to bring them greater luck!\nMan I'm a genius!
567904
Everything that you see that is made of metal comes from rocks.  Bicycles, computers, cars, cutlery - it is all taken out of rocks in the form of "ore minerals", such as bornite, chalcopyrite, argentite, cobaltite, and a million other minerals.  Computers use hundreds of different metals and alloys in their construction, all of which have to be mined out of the ground at some point.  Your computer even has gold and platinum in it.  Copper makes up the wiring in your house.\n\nIt might be easier to think of what DOESN'T come from rocks and minerals.  That would leave us with: water, wood, food, and most clothing (not synthetic clothing, mind you - that comes from oil... sort of).  Everything else is from rocks and minerals - gypsum makes up your "gyp"rock walls in your house - nails (iron) holds the house together.  Mineral aggregates are used to pave roads and sidewalks.
284631
The stones are likely insoluable salts of calcium, magnesium. A chemical analysis to show presence of these could be easily performed by dissolving in acid and using flame photometry. That will only give you a 'yes or no' answer. A definitive chemical analysis is likely beyond the scope of a school lab.
483817
Because they started as gas/liquid, and round is the lowest energy state for a liquid.\n\nLike a raindrop.
367724
Yes, m'dear, they really do.  Sadly, I saw this stunt performed at a Dungeons and Dragons party in 1988 by the company mage, Elric of Onslen.  The fart produced a blue flame.  Thankfully, this flame frightened the band of orcs we were fighting thus permitting us to claim their stash of gold.  Ah, but the stench was legendary.
929781
What kind of stone?\n.
80277
They are rocks that look like solid rocks, roughly spherical in shape, but when you crack them open or saw them open, you see the inside is lined with Amethyst crystals.  You see them alot in Museum stores or rock shops.  I like to collect them, but the really nice big ones cost a bundle.  Amethyst is the birthstone for February.  Very pretty, semi-precious gem.
122456
Both of the other anwers are right, but I thought you might also like to know why the granite is harder and can scratch the marble.\n\nThe granite is made of crystals of the minerals quartz (harndness 7), feldspar (hardness about 6) and relatively small amounts of mica (hardness 2 to 3).  This is what geologists call granite; there are a lot of other stones that stonecutters call granite, but almost all of them are made of minerals that are nearly as hard as or even harder than the stuff in geologists' granite.  A higher hardness number means a harder material.  Talc, at 1, is very soft and diamond, at 10, is very hard.\n\nMarble is made of all or mostly calcite, which has a hardness of 3.\n\nSo when you rub the granite and marble together, most of the contact is between harder mineral grains in the granite and softer mineral grains in the marble, and the granite scratches the marble.
800807
of course stones can be melted , heat them till they reach melting point (which depends on their components) and they will melt and form lava with the same chemical composition , this can be done in labratories .. and you can cool the melt again to form a hard rock .. quick cooling = fine grained rock with the same composition of course or slow cooling = course grained rock ..
242517
Granite hornblende is a source of silicon.\nAs a start, have a look here: