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Resources
Unit Notes
 Types of resources
Nonrenewable resources are those that can NOT be replaced by nature as quickly as they are being used
EX/
Fossil fuels (coal, oil, petroleum, natural gas)
Metals/alloys
Rocks and minerals
Topsoil
Forests
Fresh water
Nuclear energy
Renewable resources are those that can be replaced by nature as fast as they’re being used.
EX/
Plants (including crops)
Animals
Water
Solar energy
Wind
Hydroelectricity
Geothermal energy
Human impact (pollution or overuse) can make a renewable resource become nonrenewable. [Endangered
species are considered nonrenewable.]
 Minerals
A mineral is a naturally occurring, inorganic solid with a crystal structure.
EX/ salt, calcite, sulfur, all metals, quartz
Minerals are identified based on:
 Color (least reliable property)
 Hardness -- using Moh’s scale of hardness from 1 – 10. The higher the number, the harder the
mineral
 Luster -- how a mineral reflects light. Either metallic (shiny like a metal) or nonmetallic.
 Streak -- the true color of a mineral in powdered form, obtained by rubbing it against a
porcelain plate
 Density
 Cleavage or Fracture -- the way a mineral breaks. If it breaks along even planes of weakness, it
is said to show cleavage. If it breaks irregularly, it shows fracture.
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Crystals form in two ways:
1) Water is saturated with ions that crystallize out of solution when water evaporates
2) Magma (molten rock) cools and crystallizes as it hardens
The longer time it takes for the crystals to form, the larger the crystals will be.
A mineral that contains a useful metal or nonmetal is called an ore.
An alloy is two or more metals in solution. Since metals are solids, to get them to dissolve in one another
they must be melted first. [Some alloys are a metal and nonmetal fused together, as in steel which is
often iron and carbon.]
Examples of alloys: brass, bronze, pewter
Rocks
Rocks are made of minerals.
Rocks are classified according to how they form:
 Sedimentary Rocks form from sediments in water. Sediments can be small pieces of rock or dirt,
crystallized ions, or even the remains of living things that settle to the bottom of water.
 Clastic sedimentary rocks are made of small pieces of rocks glued or pressed together. These
rocks look and feel “dirty.” EX/ shale, sandstone (90% of the rocks in your backyard are shale.)
 Chemical sedimentary rocks are made from crystals that precipitate out of solution when water
evaporates. [If you’ve ever made rock candy, you’ve made a chemical sedimentary rock by the
same process!] EX/ rock salt
 Organic sedimentary rocks form from once-living organisms or their shells. EX/ coal, shell
limestone
Because sedimentary rocks require water to form and water is only found near Earth’s surface, these
rocks are only found near or at Earth’s surface.
 Igneous Rocks form from molten material that cools and solidifies.
 Intrusive igneous rocks cool slowly from magma deep inside Earth, therefore the crystals are
large. EX/ granite
 Extrusive igneous rocks cool quickly from lava on or near Earth’s surface, therefore the crystals
are small. EX/ obsidian, pumice
[Lava and magma are the same thing, except magma is deep inside Earth, lava is on the surface.]
Because igneous rocks form from magma/lava, they are found either deep inside Earth and/or near
volcanoes.
 Metamorphic Rocks form when intense heat (but not enough to melt) and/or pressure are put on other
rocks. Those rocks metamorphose into new rocks with new mineral crystals.
 Foliated metamorphic rocks show bands of minerals or distortions from pressure. EX/ slate
 Nonfoliated metamorphic rocks form only from intense heat so they don’t show signs of
pressure. EX/ marble
Metamorphic rocks are found deep within the Earth, especially inside mountains where pressures are
great enough to metamorphose existing rocks, and near volcanoes where nearby heat can alter existing
rocks.
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 The Rock Cycle
Any type of rock can become one of the other types of rock in the endless rock cycle.
For example, if a sedimentary rock melts, it will harden into an igneous rock. If a metamorphic rock gets
weathered down into small pieces and they get glued back together again, those sediments become a
sedimentary rock. If an igneous rock is subjected to intense heat and/or pressure, it becomes a
metamorphic rock.
 Resource Conservation
Since so many of our resources are nonrenewable, it is important that we try to conserve them by
decreasing our demand for those resources. This can be done in three ways:
 Reduce: don’t use as much of the resource in the first place.
EX/
Don’t leave the water running when you’re brushing your teeth.
Don’t drive your car when you can walk or take a bike (use less gas)
 Reuse: find another purpose for resources; use them more than once.
EX/
Use a shoebox to store stuff in instead of buying a new plastic storage container.
Use newspaper to line a birdcage.
 Recycle: make the resource into a new usable item (this means less of the resource has to taken from
the environment)
EX/
Recycle plastic to make new plastic items.
Recycle paper to be used in making lesser quality paper products.
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If we decrease the need for resources, less damage will be done to the environment in getting those
resources from the Earth. Reclamation is the process of returning the Earth to the condition it was in
before mining.