Rock Collection Science

First I went and did a bit of research to find out some information on granite and here is what I got:

Granite is the most common igneous rock in the Earth's crust. It was formed ages ago when magma (molten rock) cooled. This cooling took place below the Earth's surface and slowly enough to permit formation of crystals. It has been formed in all the periods of geological time. It commonly occurs in mountain ranges, having been formed as mountain ores. But it also occurs in level regions that were mountainous at one time but have since been worn down.

The color of granite depends on the proportions and varieties of the minerals in it. The prevailing color is gray. It is dark gray if dark minerals are abundant, and light if they are few. Greenish, pink, and blue hues are due to different kinds of feldspar.

Granite is a very hard stone, but like other rocks it may decay and crumble. Because of its great hardness it is difficult to work and so is an expensive building stone. It is used chiefly as dimension stone for paving blocks, curbing, monuments, and large buildings.

If a piece of granite is crushed to powder, one can easily pick out tiny fragments of the separate substances, or minerals, that compose it. One mineral is quartz. The particles often resemble smoky glass. Another is feldspar, next to quartz the most abundant mineral in sandy sediments. Mica, whose thin flat particles reflect light like tiny mirrors, is also present.

Then after doing all this research I took one of the pieces of rock I found, a marble rock and a hammer and I decided that I'd try to see which one is easier to break or are both the same. Well I found out that the rock I found was much more stronger than then the marble rock.

So after trying that I decided to compare the rock I found with the granite picture and with the marble rock I had to see which of the two rocks is it more similar with. Here is what I got:

Similarities and differences with the marble rock-

. It was the same color as the marble rock, gray, black and white.

2. But the patterns of the rocks were different.

3. The color of the marble rock was a much more faded and dull one than the rock I found.

4. It was much stronger than the marble rock.

Similarities and differences with the granite rock-

. The rock I found did not have all the colors the rock in the photo had but it had most of them.

2. The patterns of the rocks were the same.

3. It looked just as bright and good as the one I found.

4. It is much stronger than marble, so this probably means that it is as strong as granite.

After considering all this I concluded that the rock I found had a lot more similarities with the granite rock than the marble one. And the more I looked at the rock I found the more it looked like granite.

But after all this I still wanted to make sure that it was granite so one day when I was going out with my friends to town I brought a bigger piece of rock with me. When we passed a tiles shop I said, "I'll be two minutes I just have to go see one thing." So I went in an asked one of the people that worked there is he could tell me which rock they used for that type of tiles and he went away to check and after a few minutes he came back and told me it was granite.

So my prediction was correct. I was very happy to hear that it was granite after all. I did a lot of hard work t come to my conclusion, and I would have hated it to be wrong.

A picture of a granite rock

Basalt-

Well try as I might I can't find any basalt rock. I've collected loads and loads of rocks but none seem to fit into the description of a basalt rock. I tried looking for them over construction areas and stuff but I can't see any. So I just decided to find a picture of one and do some research on it so here is the picture and some information on basalt rock:

Basalt lava (glowing rock) oozes over basalt lava flow

Basalt Rock

One of the most abundant types of rock on Earth is basalt. It is a kind of igneous rock formed by the cooling of a certain type of molten lava. The lava cools and then hardens into a fine-grained crystalline rock. The word basalt is believed to have come from an ancient Ethiopian word, basal, meaning "a rock from which iron can be derived." Supposedly the first basalts were obtained in Ethiopia.

Basalt is dark gray or black in color and is denser than most other volcanic rocks. It contains less silica and more iron and magnesia than the other common volcanic rocks, such as rhyolite. Its chief minerals are feldspar, pyroxene, olivine, and iron oxides. Although nearly all basaltic rock is crystalline, in some cases, where the lava has cooled rapidly, it has a glassy appearance. Because of its density and toughness, basalt is often used for making roads and in the construction of buildings.

Basalt is found throughout the world. Most of the lavas that pour out of volcanoes that make up oceanic islands are basaltic. For example, the great shieldlike volcano of Mauna Loa, in Hawaii, is made up of basaltic lava flows.

As well as being the main volcanic rock of the oceans, basalt occurs on the continents. In the Columbia and Snake river regions of Washington, Oregon, and Idaho in the United States, thousands of square miles are covered with basalt. This enormous volume was poured out from great fissures, or cracks, in the Earth's crust. Basalt plateaus of similar size occur in India and Brazil. Many modern volcanoes, such as Hekla in Iceland and Mount Etna in Italy, also erupt basaltic lava.

Where the liquid-lava flows cool slowly and evenly, the newly hardened material shrinks and cracks into columns with several sides. Well-known examples of these columns can be seen at Fingal's Cave on the island of Staffa off the coast of Scotland and at the Giant's Causeway in County Antrim, Ireland. Somewhat similar columnar formations occur in the United States at the Palisades along the Hudson River in New York and at the Devils Postpile near Yosemite National Park in California.

Sedimentary Rocks-

Chalk-

I was playing on the golf course when I went into a bunker. I found a bigger stone, which was lying really close to my ball so I decided to take it out. But when I touched it, it was somewhat different from what I expected. I was not at all like the sandstones, which you usually get in bunkers or any other stone, which might have been dropped there or might have flown in with the rain, or something like that. The stone was very soft and white. So I decided that it would be interesting rock to choose for my rock collection.

I had an idea of what rock it might be. And I had a way of proving my theory was right. Sometimes the green keepers use chalk as well as sand in bunkers so that they could make them softer and more easier to get way too much sand, so when u do that u might not get out of the bunker.

So the fist thing I did was to go and collect some information on it and this is what I got:

In crayon form the mineral called chalk is a familiar classroom tool. In the natural state chalk is a relatively soft, white, fine-grained variety of limestone that forms on the bottom of seas. It is composed primarily of the shells--calcium carbonate (CaCO3)--of microscopic one-celled animals known as foraminifera. When the foraminifera die, their shells sink to the bottom of the sea and are mixed with lime muds, forming chalk deposits.

The biggest chalk deposits were formed during the Cretaceous period that began about 135 million years ago and lasted for about 70 million years. Some of this has been thrust up by geological forces, as in the famous white cliffs of Dover, England. The same formation stretches across the English Channel, rising on the coast of France. Extensive deposits also occur in Arkansas, Louisiana, Texas, and Wyoming.

Finely ground chalk is known in industry as whiting, and is used in paper, rubber goods, paint, and putty. It is used also as a soft polishing powder and in tooth powders. Substitutes for true chalk whiting are made from ordinary limestone, marble, or chemically prepared calcium carbonate.

Most blackboard chalk crayons may be made of true chalk but commonly are plaster of Paris, made from the mineral gypsum. French, or tailor's, chalk markers are a form of the mineral talc.

Chalk has been used as a drawing material for more than 10,000 years. Chalk crayons for artistic drawing usually have been confined to the colors white (limestone), black (soft black stone or a composition including lampblack), and red (natural pigments).

The colored chalk crayons used in schools for writing or drawing on chalkboards are composed of powdered pigments mixed with powdered white chalk and a non-greasy binder. A drawing material much like the chalk crayon is the pastel, which consists of any of a variety of pigments in a synthetic binder such as methyl cellulose.

After gathering this information I decided to do an old experiment, which is still used for testing to see if the rock is chalk. As you might already know chalk fizzes when acid is dropped on it. This happens because chalk is made of calcium carbonate.

So what I did was take the rock I found and carefully with a small plastic needle I poured a few drops of acid over the rock. And it started to fizz. This is how I came to the conclusion that the rock, which I found was chalk.

Limestone-

Well when I heard we had to do a rock-collecting project I knew just where to find a limestone. We have a community gardens in our neighborhood and they use limestone and marble to put around plants as decoration. So I went down to the garden and took one of the limestone's.

When I came home I decided to do some research on it. Here is what I learned:

Without help from chemistry and a microscope it would be hard to accept that the rock called limestone comes from sea shells and corals. But chemistry proves that shells and corals owe their stiffness to calcium carbonate (CaCO3), often called "carbonate of lime." Limestone also is mainly calcium carbonate; and the microscope reveals the remains of animals that formed it.

Limestone is sedimentary rock, formed from shells and other "limey" material in the oceans that in past ages covered the limestone regions. Outstanding regions of this sort in the United States are the present site of the Rocky Mountains, the valleys of the Mississippi, Ohio, and St. Lawrence rivers, and a large part of Texas.

Limestone has many important uses. It is the chief source of lime. It is used in making portland cement and in smelting iron and lead and it is an important building material.

It wears better than sandstone, is more easily shaped than granite, and weathers from nearly white to a beautiful gray. Oolitic limestone, quarried in Lawrence, Monroe, and Owen counties in Indiana, is a particularly fine building stone. Its texture resembles fish eggs, hence its name, from the Greek oion, meaning "egg." Bedford, Ind., is an important limestone quarrying center.

Crushed limestone is used on macadam roads. Farmers use ground limestone to neutralize soil acids that attack calcium and other salts needed by plants. Such protection occurs naturally when soils have a limestone foundation.

Travertine limestone and calcareous tufa consist of calcium carbonate deposited from hard water. Stalactites and stalagmites in caves are formed in the same way. Limestone rock is often riddled with caves because water and carbon dioxide dissolve the limestone. Chalk is a soft, white limestone containing the shells of foraminifera. Marble is a metamorphic, or transformed, limestone crystallized by pressure and perhaps heat.

After I had some idea of what limestone is and what it is used for I decided to start my test to see if it really was limestone or not. Now as you already might have noticed limestone is also made out of calcium carbonate. So if I add an acid to it, it would start fizzing just like the chalk.

So I set the rock on a piece of glass and carefully poured a few drops of acid with a needle on the rock. And just as I guessed it fizzed. So I was correct one of the rocks they use in the park as decoration is limestone.

Sandstone-

Well very near to my house I have the beach and lots of times I walk down when the sun is setting and just walk along the coastline. So one evening when I went I picked up one of the rocks from the beach, which I believe to be a sandstone.

When I came home I got some information on the rock, which I believed I had found and here is what I found out:

Sandstone is a sedimentary rock built of grains of sand held together by a natural cement. The most common sand in sandstone is quartz, though feldspar and rock fragments may also be present. The cement may consist of silica, calcium carbonate, iron oxide, lime, or clay. When quartz sand grains are tightly cemented with silica, they form the hard compact rock called quartzite.

Sand is a major ingredient of mortar, plaster, concrete, and asphalt paving. Bricks made of clay mixed with sand are harder and will bear a greater weight than bricks composed of clay only. Molds used in foundries for casting metal are made of sand with a clay binder.

Sand is also used as a filter to purify water and as an abrasive. It is glued to paper to make sandpaper. Blown through a hose by compressed air or steam, sand is used as sandblast to clean the walls of brick or stone buildings, to remove paint, and to clean metal articles. In the pottery and glassmaking industries, very pure quartz sands are used as a source of silica. Similar sands are required for lining the hearths of acid-steel furnaces, because pure silica is heat-resistant.

After I gathered all this information I wrote down a list of reasons why I have come to the conclusion that this is a sandstone:

. It's a soft rock.

2. I can scratch it with my nails.

3. It's made of tiny little rocks which we call sand.

4. And it looks exactly like a sandstone in one of my old school books.

I think that these four reasons are enough to classify it as a sandstone. And I think I classified the rock with its rightful name.

Rock Salt-

On very hot days like it was a few days ago and the sea dies up a bit you have rock salts left behind. Fortunately I was walking on the beach that day when I found a few. This I thought would be an excellent rock for my collection. So I took them home and did some research on them. I couldn't find too much information on salt rocks themselves but I got a bit on salt and bits which had salt rock information in it. We'll here is what I learned:

Salt is valued not only because of its properties as a condiment and preservative, but also because it is essential to the health of humans and animals. Short-term deprivation can cause nausea and weakness. Long-term deprivation causes dehydration, a progressive drop in blood pressure, coma, and finally death. (On the other hand, excessive salt consumption can also be harmful and is known to contribute to high blood pressure.) Salt is also used to cure animal hides and to remove ice and snow from pavements. Water-softening equipment uses salt, and salt is indispensable in the manufacture of certain chemicals.

The substance commonly known as table salt is sodium chloride (NaCl), though the term salt is also used in chemistry to refer to the compounds produced by the reaction of acids with bases.

Physically, table salt occurs as a cube-shaped crystal that, depending on purity, may be colorless, transparent, or translucent. Under normal conditions, salt will absorb water from the atmosphere. It also dissolves easily in water, and as it does so, it lowers the water's temperature.

Sodium chloride is by far the most common salt that exists naturally on the Earth. The oceans contain the largest amount--about 3 percent of the weight of seawater is sodium chloride. In some inland areas, the ratio may be even higher--as much as 15 percent of the weight. These naturally occurring deposits of water with an unusually high percentage of salt are called brines. They include the Dead Sea, the Great Salt Lake, and other deposits in various parts of the United States, Great Britain, Germany, France, Austria, and India. (The Salzkammergut area of Austria was named for its abundant salt deposits.)

Natural deposits of crystalline sodium chloride--known as rock salt or halite--also serve as significant sources of salt. These deposits are the products of the evaporation of seas in the distant past. They may occur as beds that lie on or near the Earth's surface or as deposits deep underground. Rock-salt deposits occur in the Punjab Salt Range in Pakistan and Iran, in the sub-Carpathian Mountain region of Europe, and in parts of the United States, Canada, Germany, Nova Scotia, and China.

Another major source of rock salt is salt domes, vertical cylinders of rock salt embedded in surrounding layers of earth. The domes apparently pierced surrounding rocks and were formed when geologic forces pushed up plugs of salt from depths as great as 50,000 feet (15,000 meters). Salt domes are often 6/10 mile (1 kilometer) or more in diameter. They occur on the North American Gulf coast, in the sub-Carpathian region of Europe, and in northern Germany.

Commercial salt is manufactured from rock salt and from seawater and brines. For some purposes rock salt may be used in its solid, raw form, but all other salt undergoes some purification process.

Salt domes and beds of rock salt that lie on or near the surface can be excavated in much the same manner as any other mineral deposit. If the salt is of sufficiently high quality, it may simply be ground, sieved, and sold. If impurities are present in unacceptable levels the rock salt may be dissolved to form a brine. Commercial salt is manufactured by treatment of the brine, as described below. Where salt deposits are too far below the surface to be mined efficiently, water may be pumped down to dissolve the deposits. The resultant brine is then collected and treated.

The reasons I believe the rock I found was rock salt is because it was in a crystal form and it was transparent. I also found it on the beach near the sea water, where there is lots of salt. And it is known that if you are careful enough u can find these rocks on some of the beaches here.

Metamorphic rocks-

Marble-

Marble is one of the major metamorphic rocks, so I knew I must have it in my collection. In my neighborhood it is very abundant because they use it for decorating around plants, building marble rock paths and for monuments. I went out a couple of days ago to one of the gardens a brought back one of the marble rocks.

The first thing I had to do was gather some information about marble rocks and here is what I got:

Sculptors and architects for centuries have used the beautiful and strong stone called marble. Its beauty and strength come from the skeletons and shells of countless millions of tiny sea animals called crustaceans.

Ages ago their mineral remains, made up of calcium carbonate, sank to the bottom of the sea. Mud and other sediments covered them and pressed them into limestone. Water, heat, and pressure then metamorphosed, or changed, the rock into marble. As marble it is more compact and crystalline. Some marble metamorphosed from dolomite, composed of calcium magnesium carbonate.

Onyx marbles did not metamorphose from limestone but are calcium carbonate deposited by water. Verd antiques are marbles made up chiefly of serpentine, a hydrous magnesium silicate. Commercially, any rock containing calcium carbonate that can be polished is called marble.

Pure marble is white. It varies widely in color, however, from white to black through almost every shade of the spectrum. Impurities such as silica, iron oxides, and graphite give marble its color and characteristic rich veining and clouding. In texture it has a wide range from fine to coarse, and it takes a good polish. Marble is easily carved for statues. Impervious to moisture and fire resistant, it is ideal for monuments and fireproof buildings. Architects use it for columns, walls, floors, and steps, both interior and exterior. Interior designers also use it to decorate such items as tabletops and fireplaces.

The ancient Greeks used Parian marble from the Island of Paros for such famous statues as the 'Venus de Milo'. They built the Parthenon in Athens of Pentelic marble from Mount Pentelicus. Pure white marble from Carrara, Italy, was used by the Romans and such Renaissance sculptors as Michelangelo and Antonio Canova. It is still favored by modern sculptors.

Marble is found in many places. American importers can select about 100 types from Italy, France, Spain, Belgium, Morocco, Portugal, and other countries. The United States produces about 120 types of marble. Vermont, Tennessee, and Georgia lead in quarrying marble as dimension stone for buildings and monuments. Missouri, Arkansas, Maryland, and Colorado are also producers. Many states quarry marble as crushed or broken stone for terrazzo flooring, roads, concrete aggregate, and other uses. The Lincoln Memorial in Washington, D.C., is made from various American marbles.

I came upon the conclusion that the rock I found was marble because it was a very pure white rock, which was pretty strong but not as strong as granite. It is easy to smooth and polish it. And the rock looks like it's made from tiny little crystals. And this description fits in perfectly with the description of a marble stone. I therefore believe that I have got this rock right.

Slate-

The other day me and my friends went to a very big and popular park here on the coast. Loads of people go there. Anyways we were sitting down on the ground and talking and I was messing with one of my friends so she threw a stone at me. I caught it and when I looked at it, I was really surprised and happy. It was a slate stone. Just the stone I was missing. I jumped up and hugged her and said "Man you saved me a lot of searching. Thanks a lot girl." It was very funny at first cause she didn't understand why I was so happy about her throwing a rock at me.

But when she found out she had a big laugh. Well when I got home I got down to searching right away. I found quite a bit of information on slate and here is what I learned:

Formed millions of years ago, slate and shale rocks have served as important materials throughout human history. Slate has been used in construction and household items, while shale contains petroleum and other minerals that can be extracted for commercial use.

Scientists have determined that most slates were originally clay sediments deposited by water. These clay beds, lying far beneath the Earth's surface, were subjected to relatively low temperature and pressure. As a result, slates were formed chiefly among older rocks, though more recent slate can be found in regions that experienced the folding and compression of mountain-building movements.

If the clay is deposited in layers and has a tendency to split along the bedding planes, it is shale. If it is tilted up at a new angle and was compressed so that it spread out and produced cleavage planes at right angles to the direction of pressure, it is slate. The tendency to split into thin slabs is so characteristic of slate that the name is sometimes applied to shale or other rocks that split in this manner. The principal minerals in slate are mica, chlorite, and quartz.

Slate was used in earlier times to make flat writing tablets called slates, tombstones, roofing tiles, and other articles that required a smooth, flat surface. Later this dark gray (sometimes blue, greenish, purplish, or even red) stone came into wide use in such items as roofing, sinks, washtubs, flooring, blackboards, billiard tabletops, and mantels. Slate is especially suitable for these uses because of its smooth, easily cleaned surface and its property of splitting into thin slabs or leaves. The different colors of slate are due to the presence of various minerals in the rock.

Shale is formed from fine-grained sediments deposited in quiet, protected waters such as the deep ocean floor, the deeper parts of continental shelves, shallow seas and bays, coastal lagoons, and river floodplains. Most shales are composed of clay minerals, quartz, and such other substances as carbonates, feldspars, iron oxides, and organic matter arranged in thin layers.

Colors in shale are caused by the presence of certain minerals and organic substances. Black shale, for example, results from organic matter, red shale from ferric iron, and green shale from ferrous iron. Shale is soft and porous, characteristics that allow it to absorb and release organic matter and minerals easily. Trapped organic material may be converted into petroleum and other hydrocarbons.

Shale has considerable economic value. Oil is extracted from shale in the United States, Brazil, and South Africa. Petroleum from this source, however, cannot be refined by methods used for crude oil. To render shale oil usable, hydrogen must be added and the mixture treated chemically to remove nitrogen and impurities. Shale in the eastern United States is a rich source of uranium. A large band of this sedimentary rock in Central Europe contains metallic sulfides, and shale deposits in eastern Germany and Poland are mined for their copper, lead, and zinc.

The reasons I believe this rock is a slate rock are because it is a blackish golden color, it's a hard rock but it splits into sheets easily. Just like a slate rock is.