Background Information:Rocks normally consist of several minerals, some essential, some accessory. A rock may be thought of as a "mineral environment." Each rock type was formed under certain specific conditions, resulting in the formation of a fairly predictable group of minerals. Rocks fall into three classes according to their origin: Igneous!edimentary"etamorphicCOAL: A sedimentary rock, formed from decayed plants, is mainly used in power plants to make electricity.LIMESTONE: A sedimentary rock, it is used mainly in the manufacture of #ortland cement, the production of lime, manufacture of paper, petrochemicals, insecticides, linoleum, fiberglass, glass, carpet backing and as the coating on many types of chewing gum.SHALE: A sedimentary rock, well stratified in thin beds. It splits unevenly more or less parallel to bedding plane and may contain fossils. It can be a component of bricks and cement.CONGLOMERATE: A sedimentary rock with a variable hardness, consisted ofrounded or angular rock or mineral fragments cemented by silica, lime, iron o$ide, etc. %sually found in mostly thick, crudely stratified layers. %sed in the construction industry.SANDSTONE: A sedimentary rock more or less rounded. &enerally thickbedded, varicolored, rough feel due to uneven surface produced by breaking around the grains. %sed principally for construction, it is easy to work, the redbrown sandstone of 'riassic age, better known as "brownstone," has been used in many eastern cities.GRANITE: An igneousplutonic rock, medium to coarsegrained that is high insilica, potassium, sodium and (uart) but low in calcium, iron and magnesium. It is widely used for architectural construction, ornamental stone and monuments.PMICE: An igneousvolcanic rock, it is a porous, brittle variety of rhyolite andis light enough to float. It is formed when magma of granite composition eruptsat the earth*s surface or intrudes the crust at shallow depths. It is used as an abrasive material in hand soaps, emery boards, etc.GABBRO: An igneousplutonic rock, generally massive, but may e$hibit a layered structure produced by successive layers of different mineral composition. It is widely used as crushed stone for concrete aggregate, road metal, railroad ballast, etc. !maller (uantities are cut and polished for dimension stone +called black granite,.BASALT: An igneous volcanic rock, dark gray to black, it is the volcanic e(uivalent of plutonic gabbro and is rich in ferromagnesian minerals. -asalt can be used in aggregate.SCHIST: A metamorphic unevengranular, medium to coarse grained, crystalline with prominent parallel mineral orientation. &oes from silvery white to all shades of gray with yellow to brown tones depending on the mineral concentration. !ome schists have graphite and some are used as building stones.GNEISS: A metamorphic uneven granular medium to coarse grained crystalline with more or less parallel mineral orientation. .olors are too variable to be of diagnostic value. /ue to physical and chemical similarity between many gneisses and plutonic igneous rocks some are used as building stones and other structural purposes.!ART"ITE: A metamorphic or sedimentary rock with crystalline te$ture, consists of rounded (uart) grains cemented by crystalline (uart), generally white, light gray or yellow to brown. !ame uses as sandstone.MARBLE: A metamorphic evengranular grain to medium grained and may beuneven granular and coarse grained in calcsilicate rock. 'he normal color is white but accessory minerals act as coloring agents and may produce a variety of colors. /epending upon its purity, te$ture, color and marbled pattern it is (uarried for use as dimension stone for statuary, architectural and ornamental purposes. /olomite rich marble may be a source for magnesium and is used as an ingredient in the manufacture of refracting materials.History - How we used Rocks & minerals way back whenStone Age: Very long ago, our ancestors used rocks for tools. This was known as the Stone Age. This period of human development lasted a long time - about 3 1/ million years. This is also known as pre-historic times This era ended about !,""" to #, $"" years ago when people learned how to make metal. %bsidian and flint were used for knives and spears. &iver rocks were used to break other things. 'aves were used as places to live and rocks and boulders were used to sit on and to build fire pits.Copper Age: (epending on what part of the world people lived in, this period was then followed by the Copper Age when people discovered how to smelt )melt using high heat* copper ore. +n ,ritain, it was about !,$"" years ago and lasted for several centuries This was not a long period because people -uickly learned how to make other metals. (uring this time, cities were being built and building stones were beingused a lot.Bronze Age: This was then followed by the Bronze Age about #,""" years ago. ,ron.e is an alloy of copper. (uring this time, people learned how to mi/ minerals to produce metals like copper, bron.e, leadand tin by smelting them. Smelting ore is when you melt crushed rocks with minerals in them at very high temperatures. ,y adding other chemicals and minerals, the metals separate out and the metal can be poured off. 0melting is like melting with a purpose. The melted rock that is not metal is called slag.ronAge: This period was then followed by the ron Agewhich started about 3,""" years ago. (uring the ,ron.e 1ge they learned how to e/tract / make metal from rocks. (uring the +ron 1ge they learned how to make tools 2 implements )things they used* out of metal. +ron is very strong and made very good and long lasting tools. These tools also meant that stone could be shaped more easily and many empires built buildings, structures and roads that still can be seen today. 0ince that time period, people have built many cities and used minerals e/tensively.!odern Age: +n !odern "imes, since about 13"" '4 )or !"" years ago* we have been using rocks and minerals at an ever increasing rate as we build machines, cities and consume a great number of 5things5 in a lifetime. %ur uses of rocks and minerals can be divided into $ categories6o #$ Building Stoneso %$ !achines & "oolso &$ Arti'actso ($ Consumables & )rocesses o *$ +ecorationso ,$ -ewellery 7777777777777777777777777777Rock# and Min$ra%# inE&$r'da' Lif$ .an you picture a world without rocks0 If there were no rocks there would be no food, toothpaste, pencils, silverware, plates, makeup, statues and so much more. If there were no rocks we wouldn1t have soil for food. !oil is made mostly of rock pieces and minerals. 'here would be no tools, no shelter, no 2ewelry, no food, no roads, not much left. 'oday we have rocks and we can do and make most anything.Gra()it$ is used to make pencils. !late is used to make blackboards and patios. Lim$#ton$ is used to make chalk. 3e use graphite and slate to make fireplaces..oal is used to heat homes. .obalt is used for making super alloys for 2et engines, chemicals, and much more. 4luorite is use in your favorite toothpaste as is limestone and calcium carbonate. &old is used in dentistry, medicine, 2ewelry, and art. G'(#um is used in the manufacture of sheetrock. 5alite is used in human and animal diet food.P'rit$ is used in the manufacture of sulfur, sulfuric acid, and sulfur dio$ide. !ulfurisnecessary to grow our food. "inc is used in making nails and roofing. !ilica sand, talc, feldspar and soda ash are used in glass and ceramics. 'hey can also be found in insulation and paint. 3e use granite in monuments as well as kitchen countertops and even tombstones. #olishing materials are made from pumice. 6olcanic ash and pumice make kitty litter. "ost electrical components contain (uart). "agnetite is an or$ of iron used in making steel, kitchen appliances, ship building, trains highways even nails7 4rom carpet to the foundation of your house, rocks and minerals are used in everyday life.3e use rocks in medicine too. 8ne kind of rock in medicine is -ismuth. -ismuth is usedfor an upset stomach. 9ou know the bottle with the famous pink li(uid0 !ulphur is used in making drugs. !ilver is used in making dental and medical e(uipment. "agnetite is used in medicine, too. Another rock used in medicine is -oron. !ome people say this mineral can strengthen bones and make more muscle. 3e do not know this for sure, but we do know that vitamins and minerals can be used to make you healthier..an you imagine your world without rocks and minerals0___________________________________________________________________#$ Building Stones . /ses o' Rocks & !inerals 8ost of the rock used in construction comes from -uarries. 9uarries are places where sand, gravel and stone are e/cavated for building materials. 9uarries are great places to find fossil 2 mineral specimens as well since the blasting of the rock e/poses rocks that are beneath the surface. ,uildings 1lthough wood, straw and mud is used for houses in some parts of the word, most cities today are built of stones and metal )minerals*. 8any rock 2 minerals are used to make buildings. 'oncrete, steel, glass and wallboard are all common in modern buildings. :ranite is used to decorate the outsides of buildings as well as tiles for floors and counters. +t is a hard stone that resists wear and weathering. 8arble is used for interior walls and floors where there is less traffic )such as bathrooms* because it is soft. 8any buildings built out of stone over """ years ago can still be seen in places where ancient civili.ations e/isted like &ome, :reece, ;eru and 'entral1merica.

&oads 2 ,ridges 1 lot of crushed stone and concreteis used in the building of roads,highways, tunnels, bridges, airportsand parking lots. 1ggregate1ggregate is what pieces of rocks that havebeen blasted is called. The gravel you see in driveways 2 atthe side of the road are aggregate. 0ometimes you won