Modern Life and The Rock
Society places a high
value on rock and mineral resources. Mining plays an integral
role in producing modern life creature comforts, industrial
production and economic success. People use mined, mineral
resources each day, in almost everything we do. Because they are
so much a basic part of our lives, we don't think of them very
would like to tell you a little about how rocks and minerals are
used by you everyday and you probably never even knew it!
looks glassy. Calcite has smooth surfaces but will not stand up
on all of them. Calcite can scratch a fingernail. Steel can
scratch calcite. Calcite powder fizzes in vinegar. Clear calcite
makes things look double. It is very closely related to
Limestone, Lime, Chalk and Calcium Carbonate. Calcite is a common
mineral. It often forms beautiful, pointed crystals. If calcite
is not pure, it can be found in almost any color. The clearest
calcite is called Iceland spar because it is common in Iceland.
Stalactites and stalagmites in caves are made of calcite. Calcite
is a main rock-forming mineral of sedimentary rocks. It is also
found in metamorphic rocks. Calcite forms when the chemical
called calcium carbonate settles out of solution. Calcite is used
to make cement and lime for mortar in buildings. If you want to
know if you have found calcite, scratch the surface of the rock.
Do not wipe off the white substance which will appear. Place a
small drop of vinegar on the scratch. It should bubble and fizz.
Calcium carbonate is a white powder or colorless crystalline
compound, CaCO3, found mainly in limestone, marble, and chalk in
the form of the mineral calcite; used in making lime, paints,
plastics. It can be found in the production of Fertilizers, water
treatment, food preservatives and animal feeds.
Limestone is light colored (white, gray, or tan). Limestone may
be fine grained or made up of shells and shell pieces. Limestone
powder fizzes in vinegar. Limestone is a common sedimentary rock.
One type of limestone contains fossils. Limestone occurs in
layers, or beds. The beds may be up to 30 miles thick! Limestone
may be dissolved and redeposited in such places as rock
fractures, caves, hot springs, and geysers. Various limestones
originate in different ways, but all form in water. The most
common limestone forms when lime (a compound of calcium and
oxygen) undergoes a chemical process. It settles out of the water
and builds up in layers that harden into limestone. Another type
of limestone is formed by organisms. Corals, snails, clams, and
one-celled organisms use calcite to make shells. When the
organisms dies, the shells settle to the bottom. Thick layers of
shells build up and harden into limestone. The fossil remains of
organisms can often be seen in this type of limestone. Limestone
is made up of the mineral calcite. 400 million years ago, the
mid-continent of the United States was covered in a broad shallow
sea. Much of today's modern day limestone deposits were formed
from this sea.
Limestone is used in extensively in
buildings, both inside and out. It is an important part of mortar
and cements. Limestone can be used as an environmental cleaning
agent in many air and water pollution abatement systems.
Cement is a
powdered substance made of burned lime, clay, shale or gypsum
mixed with water and sand to make mortar, or with water, sand and
gravel to make concrete. Small pieces of pumice are mixed with
cement and plaster to give these construction materials a lighter
weight. Pumice is usually gray or white. Pumice is made up of
silky glass fibers and many air holes. Most pumice will float on
water. Pumice is volcanic glass. Thin glass walls separate the
many air holes. Because of the air holes, pumice can float for
many weeks before it becomes waterlogged and sinks. Pieces of
pumice drift ashore almost every seacoast. Pumice forms when lava
turns solid while gases are still bubbling from it. Pumice has a
spongy and frothy texture.
Concrete is a hard, compact building material
formed when a mixture of cement, sand, gravel and water dries.
Perlite is used in concrete and plaster and as a soil for potting
plants. Perlite is formed from heated obsidian rock. When
obsidian that contains water is heated, it expands and pops just
as popcorn does and forms perlite.
is used for building and repairing roads, building construction,
concrete, cement, metallurgical fluxing.
Dolomite is used in building stone, road
aggregate and agricultural lime. It is limestone which contains
magnesium carbonate in an amount equal to the calcium carbonate
content of the stone.
Powdered limestone may be used
to improve poor soil. Lime is obtained by the
action of heat on limestone, shells, and other material
containing calcium carbonate, used in mortar and cement, hydrated
it neutralizes acid soil.
Chalk is a type of lime or limestone,
essentially calcium, carbonate, calcite. Chalks is a limestone
made up of shells from microscopic marine organisms. Natural
chalk is white. Chalk is so soft that a fingernail can scratch
it. Chalk powder fizzes in vinegar. The White Cliffs of Dover,
England, contain large deposits of chalk.
Phosphate Ore, once separated from limestone and
silica sand by milling, is made into fertilizers, industrial
chemical compounds, and additives to food and toothpaste.
Marble is a hard crystalline or granular
metamorphic limestone in varied colors and patterns, capable of
taking a high polish; it is used in building stone and memorials.
Most marble is white or light colored. Most marble is coarse
grained. Marble can be scratched by steel. Vinegar makes powdered
marble fizz. The best known marbles are the pure white marbles
from Greece. Ancient Greece used marbles for statues and
buildings, such as the Parthenon. Some marbles contain colored
minerals. Marble forms from limestone. Great heat and pressure
melt the calcite in the limestone. The calcite regrows into
larger crystals. The hardened rock is marble. Marble is quite
soft and is easy to cut, carve and polish. Marbles are made into
statues, monuments, grave markers, and into elaborate designs for
Wollastonite is most commonly found in
metamorphosed limestones. This mineral has a unique particle
shape (acicular or fibrous) and has a white color when pure. It
is used in ceramics, as a filler in paint and as a filler in
Sphalerite is the material which produces zinc. Spalerite
sometimes resembles the rock, Galena, which is used to produce
lead. Its name comes from a Greek word meaning
"tricky", because ancient Greek metalworkers often
mistook it for galena and were annoyed when they couldn't get
lead from it. The yellowish-brown ore is usually found within
white and gray dolomitic limestone host rocks. Zinc has a wide
variety of uses. Zinc is refined and used throughout the world
largely to protect steel against rust. More than 5.2 million
metric tons of this mineral are consumed annually. Zinc-coated
steel, commonly called galvanized steel, helps to make steel last
longer with very little maintenance. Nearly 40 pounds of zinc is
in a typical automobile, found primarily on steel body panels and
chassis parts. And zinc oxide, which is needed for curing rubber,
is in every tire. Zinc oxide is used to soothe baby's diaper rash
and your skin when you have sunburn, poison ivy, and blisters.
Zinc, heated to a liquid, is injected into die-casting machines
and shaped to produce intricate parts. Zinc die castings are used
in a wide array of precision parts for automobiles, airplanes,
and appliances. Zinc is used for refrigerator handles, dishwasher
buttons, and pull-knobs on washing machines. Brass, an alloy of
zinc and copper, has been used for over 3,000 years. Brass, is
fashioned into everything from door knobs to trumpets and beds.
Zinc air batteries power hearing aids and rechargeable battery
packs for lap-top computers. Zinc is also used in some
pharmaceutical products as well as in some paints, chemicals, and
Zinc occurs naturally in the body
and is an indispensable nutrient for humans, animals, and plants.
Because it takes zinc to produce protein, the "building
blocks" of life, zinc is essential for growth. Zinc is most
available to the body from meat. A zinc-deficient diet can lead
to slowed growth, dry skin conditions, mental lethargy, loss of
appetite and eating disorders, impaired vision, and increased
susceptibility to infection.
Granite is usually light colored, from nearly white to shades of
gray and pink. Granite is coarse grained. The grains are large
enough to see with the naked eye. The quartz in granite can
scratch steel. Granite is the most common coarse-grained igneous
rock. It is made up of quartz, feldspar, and grains of a dark
mineral like potassium, mica, hornblende. Granite is hard and
wears slowly. It is an igneous rock. Granite is frequently used
in building stone and memorials. The Vietnam Veterans War
Memorial in Washington, D.C. is made of polished black granite.
Plaster of Paris is made from a
rock material called "gypsum". It’s a special
material that doctors once used to make casts when people broke
their arms and legs. The strangest thing happens to plaster of
paris when it begins drying. Do you know what that is? It gets
hotter when it begins to dry. This is called an
"exothermic" reaction. Gypsum is considered to be a hydrated sulfate
of calcium, occurring naturally in sedimentary rock; used in
Plaster of Paris (wallboard) and chalk.
Gypsum is an evaporite and a product of precipitation from
saturated brines or ancient playa lakes and restricted marine
basins. This means that gypsum forms when seawater evaporates
under arid conditions. The principle use of gypsum is in the
production of wallboard. It is also a primary component of stucco
and plasters, and in the manufacture of cement. Very high grade
gypsum also finds food grade and pharmaceutical applications.
Gypsum can form sulfur through a chemical reaction. Natural
sulfur is usually light yellow in color. Sulfur
crystals are almost transparent. Sulfur crystals may be
transparent yellow. Sulfur can appear to glisten or look greasy.
Sulfur can be scratched with a fingernail. It has an
identifiable, pungent odor. People sometimes called sulfur
"brimstone" because, generally, sulfur can be found
around the mouth of volcanoes or from the around the edges of hot
springs. Many major sulfur deposits are in sedimentary rocks and
can typically be found within quarries. In Central and South
America, sulfur has been quarried from the craters of extinct
volcanoes. Sulfur melts and burns at low temperatures.The warmth
of a hand will cause sulfur crystals to expand at the surface and
crack; you can even hear the crystals crackling. Specimens should
be kept out of sunlight and handled as little as possible.
Sulfur is a mainstay of the chemical industry. It is used to make
gunpowder, found on match tips and to make sulfuric acid, the
acid in car batteries. Sulfur is used to make rubber, synthetic
fibers, plastics, pigments, explosives, fertilizers, dyes, soil
conditioners, insecticides, and in making paper. How can you tell
if your rock contains sulfur? Tear some paper into tiny pieces
like confetti and then rub the sulfur with a scrap of wool. Touch
the rubbed sulfur to the paper. The sulfur becomes charged with
static electricity and will attract such things as little bits of
Pyrite consists of iron and sulfur and occurs in
all classes of rock. Pyrite is often called "fool's
gold" because it looks like gold. When pyrite is melted, the
iron and sulfur in it separates. The sulfur is used to make
sulfuric acid, the kind of acid in car batteries. Iron is
produced as a by-product. Iron is used to make electric
appliances, automobiles, buildings, office equipment, beverage
and food cans and other containers, tools, and machinery.
Quartz crystals look glassy. A quartz crystal is six sided. It
has a pointed tip and lines that run across each side. Quartz is
very hard. Steel cannot scratch it. Quartz is found in every
class of rock. Sand forms when quartz wears away from these rocks
and is broken into tiny pieces. Most light-colored sand beaches
are made up of tiny pieces of quartz. Some gems are quartz that
is colored by other minerals. Purple quartz is called amethyst.
Gray or black quartz is called smoky quartz. Quartz with uneven
bands of color is called agate. Quartz crystals form as silica
solutions cool in igneous, sedimentary, or metamorphic rocks.
Colored quartz is often cut and polished to make jewelry. Quartz
crystals cut in a certain way produce a small amount of
electricity. This effect makes quartz crystals useful in radios,
clocks, and watches. Quartz crystals can be melted and formed
into lens and prisms. They are also used in heat lamps and sun
lamps. Sand, or tiny quartz pieces, is used in making glass,
porcelain, paints, abrasives, scouring soups, and ceramic ware.
Use a hand lens to identify if you have a piece of quartz, look
for the small lines that run across the sides of the crystal.
These lines are on all quartz crystals.
Sand is a type of quartz. Sand grains are used
in concrete, glass and industrial production. Sand on the beaches of
Florida's Panhandle region sparkles white because it is nearly
pure quartz. Silica is a mineral found in quartz and sand used in
insulation, light bulbs, and TV's.
are usually light colored (white, gray, or yellow) but sometimes
dark red. Sandstones are grainy, gritty, and feel rough.
Sandstones are made mostly from quartz and can scratch steel.
Sandstone breaks around the rounded quartz pieces rather than
through them. This is why sandstone is not as sparkly as glass.
Some sandstones contain iron oxide, or rust. The rust makes these
sandstones dark brownish red. Such sandstone was used to build
New York City's famous "brownstone" apartments.
Dinosaur footprints are found in sandstone quarries in
Connecticut. Sandstone forms from old sand dunes or when quartz
sand grains settle out of water. A cement material, such as
calcite, dissolves in water and seeps down through the sand. It
glues the grains together to form sandstone. Sandstone is a
sedimentary rock composed largely of sand grains, mostly quartz
worn down by wind, water and ice, held together by silica, or
lime; used in building stone, abrasives, concrete and mortar
mixes, bedding materials, and playground sand.
Sandstone main use is in construction. It is easy to shape and
does not wear easily. Sandstone is also important because of the
spaces, or pores, between the grains. Deep in the earth,
sandstone stores petroleum. Closer to the surface, sandstone
stores groundwater. Sandstone is used for glass grinding, metal
polishing, and sandblasting. It is also used to filter sand to
remove bacteria and sediment from water supplies.
Quartzite forms from sandstone. Great heat and
pressure melt the sandstone quartz grains together very tightly
to form quartzite. Quartzite is usually light colored (white,
gray, or yellow) but sometimes is dark red. Quartzite is made up
of fine, shiny grains. the quartz in quartzite can scratch steel.
Quartzites are among the hardest and most resistant of all rocks.
They are made up mostly of quartz particles. Quartzite breaks
right through the quartz grains. These broken grains make
quartzite look sparkly.
Quartzite is used for decorations as slabs or as broken pieces.
Powdered quartzite is used to make some sandpapers, scouring
compounds, and metal polishes. It is also used for roofing
granules, road and sidewalk surfacing, in concrete, and as a
substitute for sand and grave in other construction.
Shales are usually gray but vary from black to dull red. Shales
are very fine grained. Shales are usually thin bedded with fairly
uniform texture. Shales split into flat, shell-like fragments
with curved edges. Shales can be scratched by steel. Shale is a
sedimentary rock; fine grained, thinly bedded rock, largely
formed by hardened clay, mud, and silt; splits into thin layers;
it is used in cement and bricks. It is also used in concrete
block, structural concrete, and highway surfacing.
Shales are soft and easily eroded rocks. They can be split with
little effort. Some shales contain many fossils. Shales are
mainly clay sediments that were deposited in the quiet
environment of lake and ocean bottoms and then hardened into
rock. Shales are used in the manufacture of cement, bricks,
pottery and other ceramic products. Some shales are oil
reservoirs. Billions of tons of oil shale are a potential source
of petroleum for future use. The Chattanooga Shale in Tennessee
contains as much as 15 gallons of oil per ton of shale and about
.006 percent uranium, but at present neither is economical to
Slate is commonly black or gray but may be almost any color.
Slate is very fine grained. Slate breaks into flat plates with
thin layers. Slate can be scratched by steel. Wet slate has an
odor. Slate forms when shale, a sedimentary rock made of clay, is
subjected to heat and pressure. Slate cleaves naturally into
smooth-surfaced layers; it is primarily used as building stone
and in blackboards.
Slate is very durable. It lasts for thousands of years without
changing or deteriorating. Most of the slate mined in the United
States comes from the area of the Appalachian Mountains. Slate
was formerly used for blackboards. Slate is widely used for
roofing, for flagstones to pave patios, and to face buildings.
Pulverized to rock flour, it is used as a filler in paints,
linoleum, and other products.
Galena crystals are usually cubes. Galena is heavy. Galena has a
bright, silvery-gray, metallic shine. Galena is a soft mineral.
Steel can scratch it. Galena is composed of a compound of lead
and sulfur. Galena is a main source of lead. Galena is found in
veins, pockets, and replacement deposits in rocks made of a
chemical called carbonate.
Galena, has been known for centuries, and lead, smelted easily
from it, has been used since ancient times. The ancient Romans
were the first to use lead and to make pipes to take water to and
from their great cities. Lead from the mineral galena is used in
car batteries and other types of batteries. Lead is also used in
hospitals and labs to shield people from radiation. A lead
compound is used in gasolines to prevent engine
"knock". Other uses include red lead for coating
construction steel, lead foil for toothpaste tubes, solder for
cans and containers, and soundproofing for rooms and machinery.
Talc is usually apple-green, white or gray. Talc has a pearly
shine. Talc feels greasy and slippery feel. Talc is so soft it
can be scratched with a fingernail. Talc is fine grained. Another
name for talc is soapstone. Talc forms when magnesium-rich rocks
are changed, especially by heated water. The most familiar
product made from talc is talcum powder. Talc does not conduct
heat or electricity well and is resistant to acids. It is used
for laboratory table tops and chemical and heat resistant sinks
and vats. It is also widely used as a lubricant, a source of
magnesium in refractory ceramics, and as insulation in electrical
In the United States, most of our talc is mined in Montana,
Texas, New York, and Vermont. Large deposits of soapstone can be
found in the metamorphic rocks of the Appalachian Mountains.
Eskimos carved lamps and pots from soapstone. The Chinese often
used talc for carving figurines. Tailors use small pieces of talc
to mark cloth.
Coal is black or dark brown in color. Coal is lightweight. Coal
may have a glassy shine. Coal can burn. Coal is the most
widespread and abundant energy resource in the United States.
Coal-bearing rocks occur in 37 or our 50 states. Sometimes, well
preserved plant parts can still be seen. Coal is made of the
element carbon and is usually classified as a sedimentary rock
because it occurs in layers, or beds. Coal is the product of
decomposition, compression, densification, and concentration of
carbon from dense prehistoric swamps and bogs. Peat, is
considered to be the first stage in the formation of coal. Peat
turns into lignite (brown coal), which turns into bituminous
(soft) coal, and eventually to anthracite (hard) coal.
Steadily growing energy requirements have focused attention on
the use of coal as an energy source. Electric utilities use
nearly 88 percent of the coal produced in the United States.
Other large consumers of coal products are chemical and glass
manufacturers, paper mills, and the steel and iron industries.
The by-products of coal serve as the basis for many items used
daily by Americans such as plastics, road-building materials,
perfume, linoleum, synthetic rubber, charcoal briquettes,
billiard balls, rubber cement and roofing shingles.
Borax comes from the rock called Kernite. Kernite is used in the
production of boric acid and borax. Boric acid is used in the
production of textile fiberglass (cars, boats, circuit boards,
roofing shingles), ceramics (glazes), chemicals (corrosion
inhibitors, insecticides, pharmaceuticals), and specialty glass
(heat resistant glass, laboratory glass). Sodium borate, a white,
anhydrous, crystalline salt with an alkaline taste; it is used as
a flux in manufacturing of glass, soap, enamel and artificial
gems. Several borate ores, including borax, colemanite and
ulexite, can be found at the U.S. Borax mine near Boron,
California’s largest mine. The mine supplies nearly half the
world’s demand for refined borates.
An earthy material composed of silicates, used for brick, tile,
porcelain, sewer pipes, and cement. Clays can be used for
ceramics, rubber, paint and drilling mud. It is formed by the
weathering of rock.
Kaolin is also known as China clay. Relatively
pure deposits of kaolin are used for coating and filling paper,
as a component of ceramics, and as a filler in paint, plastics,
and rubber. Kaolin is Geogia's most valuable single mineral
Feldspar is usually white or pink. It normally has a pearly shine
and a greasy luster. Feldspar breaks into flat pieces. Feldspars
are the most common group of minerals. A feldspar called
othoclase breaks into flat, rectangular pieces. Plagioclase
feldspar breaks into flat pieces that usually have curved edges.
Plagioclase has small lines that run across the flat surface.
Feldspars are important rock-forming minerals and are found in
many kinds of igneous and metamorphic rocks. Feldspars can form
in a wide range of temperatures and pressures. They are made up
of aluminum compound and several other metals. Feldspar
ultimately decomposes into clay minerals. Feldspars are used to
make ceramics and ceramic glazes. The feldspar called moonstone
is used as gemstone; it is a birthstone for June.
It can be considered
a crystalline minerals made up of aluminum silicates with sodium,
potassium, or calcium, usually glassy; it is used as flux in
glass and ceramic manufacture, also used in abrasives, fillers in
paint and plastics and in insulation.
Don't use color as a
way of identifying feldspar. Tilt the feldspar back and forth in
the light and look for a pearly shine. Lay it on the table. Does
it lie flat? Feldspar breaks into pieces that usually have flat
top and bottom surfaces.
Graphite is a soft, smooth, slippery-feeling substance found
mostly in large lumps or flattish, six sided flakes in rocks. It
splits easily into thin sheets and can also easily be crushed
into powder. Graphite is one of the two mineral forms of carbon,
and although it is soft and easily broken, the other form is the
hardest substance known, diamonds.
When you write with a "lead" pencil, you're not really
writing with lead at all. The dark marks are made of by the
mineral graphite. People first began using sticks of graphite as
writing tools in England in the 1500's. Today, powdered graphite
is mixed with clay and water to form a paste that's squeezed out
into long strings by machines. The strings are cut to pencil
sized lengths and baked in ovens until hard. Each length is then
fitted into two pieces of wood.
Graphite can take alot of heat without melting so it is used to
make electrodes through which electricity is sent into things. It
is slick and slippery without being gummy like grease so graphite
powder is used to lubricate locks and clocks.
A white, tasteless powder, used in insulation and firebrick; used
also in a mild laxative and antacid.
Mica has a pearly shine. Mica splits into thin, transparent
sheets. Micas are common rock-forming minerals. They are found in
most granites. Light colored mica (muscovite) is the most common
type. Black mica is called biotite. Mica that explodes like
popcorn when heated is called vermiculite. Micas form in igneous
and metamorphic rocks. Thin transparent sheets of mica (muscovite
called isinglass) are used as windows in iron stoves. Micas are
used as insulators in electronic equipment. Vermiculite is used
for house insulation and as a type of soil for growing plants.
Mica can be found in many beauty supplies and make-ups. Powdered
mica mixed with water forms a white, greasy material that shines.
It is used in paints and in the printing of shiny designs on
wallpaper. Mica belongs to a family of colored or transparent
minerals that separates into very thin leaves; it is frequently
used in such things as electronics, electrical, insulators,
filler and extender in plasterboard, cement, paint and drilling
mud. Don't use color as a way of identifying mica. Peel off one
thin sheet with your fingernail. The sheet will look like
A hard, fine-grained white ceramic consisting of clay, quartz,
and feldspar, used for sinks, bathtubs, toilets.
Heavy material such as water, sand or iron which has no function
in machine except the increasing of weight. Crushed stone is used
as ballast by railroad companies; it is laid in railroad track
beds. Mixed with soil, it helps control erosion.
of pitch, tar or asphalt in their natural states; soft coal that
produces much smoke and ash.
A type of excavating equipment which casts a rope-hung bucket a
distance and collects material by pulling the bucket toward
itself on the ground with a second rope.
A large, barge-like machine used in underwater excavation.
A substance used to promote fusion of metals or minerals.
element that lacks most of the typical metallic properties and is
able to form chemical compounds with hydrogen.
The soil or rock that covers a deposit.
Any finely divided solid which has settled out, as from
A place where crushed stone is freed from impurities or dust by