Personal Information: My name is Kay Cartledge. I teach
a self-cotained learning disability class
at North Augusta Elementary. I presently have ten male students
in my class.
Unit Overview: My unit will be on the varied earth materials
that have different physical properties and uses, which will include rocks,
minerals, water, and soil. Using the South Carolina State Science
Standards for third grade, my students will increase their knowledge of
earth science using various earth materials and activities. My students
will complete science experiments using the scientific method and expand
their knowledge of the physical properties of our land.
Lesson Title: Our World of Minerals
Lesson Objective: The learner will be able to define the
The learner will be able to give examples of minerals and their uses.
The learner will be able to state the four main characteristics of minerals.
What is a Mineral?
An object that has never been alive, was formed in nature,
and the atoms are arranged in a regular pattern, which form
solid units called crystals, is said to be a mineral.
A mineral has the same chemical makeup wherever it is found.
In higher grades, a mineral is usually defined as a naturally occurring
solid substance consisting of a single element or compound. There
are no two minerals that are exactly the same. Minerals have different
properties and different uses. Minerals are formed in soil
and are also found on the moon, Mercury, Venus, and Mars.
A mineralogists is a scientist who studies minerals. Minerals
are usually a compound of two or more elements. Some minerals such
as gold and sulfur are made of only one element. The common elements
that form minerals are oxygen and silicon. Other elements include
aluminum, iron, calcium, sodium, potassium, and magnesium. Our land
and our oceans rest on a bed of rock made of minerals. Rocks found
on the earth's surface are said to contain minerals. There are about
kinds of minerals, but only 100 are said to be common minerals.
Minerals are dug from the earth, and man makes many products
using minerals. He uses minerals to make cement and steel,
which are used to build buildings. Minerals are used to make fertilizers
for farming, chemicals for manufacturing, and many other products.
Graphite is a common mineral that is used in making "lead" pencils,
and rare minerals such as gold and silver are used for jewelry
and money. Many people think that any substance that is taken from
the earth is a mineral. Coal, petroleum, natural gas, and sand are
taken from the earth, but they are not minerals. Many foods and water
contain substances like calcium, iron, and phosphorus. Mineralogists
do not consider any of these to be minerals. Minerals will differ
greatly in appearance and the way they feel. Some minerals may have
glass-like surfaces and sparkle when the light shines on them. Other
minerals may be dull and greasy. Some minerals are hard enough to
cut glass, while others are soft enough to scratch with your fingernail.
Minerals are said to have four main characteristics: (1)
(2) cleavage, (3) hardness, and (4) color.
Luster of a mineral may be metallic or nonmetallic.
Minerals that shine like a metal are said to be metallic. Some examples
of metallic minerals include galena, gold, and ilmenite. Minerals
with nonmetallic luster will often vary in appearance. For example,
tale has a surface that resembles pearls, while quartz looks glassy and
Cleavage occurs when a mineral is split into pieces that
have flat surfaces. Minerals split differently. Some
minerals only split in one direction, while others split in several directions.
Another difference is the angles in which the flat surfaces meet.
For example, Halite has three cleavage directions, and when it breaks,
it separates into small cubes. A pyramid is formed as a diamond may
split in four directions.
Hardness is tested in minerals by scratching one mineral
with another. Mineralogists use a scale, Mohs Hardness Scale,
to determine the hardness of a given mineral. One mineral is scratched
with another mineral, and the harder mineral scratches the softer mineral.
A German mineralogist, Friedrich Mohs, invented the scale in 1822.
A list of ten minerals are numbered one to ten, from the softest to the
hardest. The hardness of other minerals is determined by whether
they scratch, or are scratched, by the minerals in the Mohs Scale.
Color in some minerals is determined by the make up of the
crystals. The red of cinnabar, the black of ilmenite, and the
green of serpentine all result from the chemical make up of these minerals.
In other minerals, color may be determined from the chemical impurities.
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