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South Florida Science Museum
Minerals 101 Program Curriculum
PROGRAM DESCRIPTION
This class will lead students to understand the differences between rocks and minerals. Through
the investigation of an assortment of minerals, students will study different physical
characteristics and properties of these natural gems and compare their observations with the rest
of the class.
SUNSHINE STATE STANDARDS
Grades 3-5
SC.3.P.8.3: Compare materials and objects according to properties such as size, shape, color,
texture, and hardness.
SC.4.E.6.1: Identify the three categories of rocks: igneous, (formed from molten rock);
sedimentary (pieces of other rocks and fossilized organisms); and metamorphic (formed from
heat and pressure).
SC.4.E.6.2: Identify the physical properties of common earth-forming minerals, including
hardness, color, luster, cleavage, and streak color, and recognize the role of minerals in the
formation of rocks.
SC.4.P.8.1: Measure and compare objects and materials based on their physical properties
including: mass, shape, volume, color, hardness, texture, odor, taste, attraction to magnets.
SC.5.P.8.3: Demonstrate and explain that mixtures of solids can be separated based on
observable properties of their parts such as particle size, shape, color, and magnetic attraction.
Grades 6-8
SC.8.P.8.4: Classify and compare substances on the basis of characteristic physical properties
that can be demonstrated or measured; for example, density, thermal or electrical conductivity,
solubility, magnetic properties, melting and boiling points, and know that these properties are
independent of the amount of the sample.
VOCABULARY
Density: a measure of the quantity of some physical property.
Heterogeneous: consisting of dissimilar elements or parts.
Homogeneous: of the same or similar nature or kind.
Inorganic: not arising in normal growth; artificial.
Luster: describes how a mineral appears to reflect light, particularly how brilliant or dull the
mineral is.
Mineral: a naturally occurring, homogeneous inorganic solid substance having a definite
chemical composition and characteristic crystalline structure, color, and hardness.
Mineralologist: a scientist that studies minerals.
Organic: of, relating to, or derived from living organisms.
Physical properties: any aspect of an object or substance that can be measured or perceived
without changing its identity.
Rock: a naturally occurring aggregate of minerals and/or mineraloids.
Streak: the color of a crushed mineral's powder, which may differ from the actual color of the
mineral.
SET UP
Students work in pairs each pair has a mineral box. Each student will have a mineral
identification worksheet and a pencil. Set these up before the students arrive. The mineral box
is labeled 1-18 the student working on the left of the box gets 1-9 and the student on the right of
the box works on minerals 10-18.
SCRIPT
What is a Mineral?
When you hear the world mineral, it might make you think of rocks or sand. But what exactly is
a mineral? A mineral is anything that is solid, natural, and inorganic. You know that a solid is
something that holds its own shape, unlike a liquid or a gas. Something that is natural can be
found in nature, rather than being made in a factory by people. Minerals are naturally in the
Earth’s crust. In fact, the Earth’s crust is made almost entirely out of minerals! So it is easy to
understand that all minerals are solid and natural. So what does that word “inorganic” mean?
It’s a little tricky. Something that is inorganic is not alive, nor has it ever been alive, nor is it
made out of anything that was once alive. Inorganic means the opposite of organic. Something
that is organic is alive, or was alive, or is made out of stuff that used to be alive. All people,
plants, and animals are organic. Even after something dies, it is still organic, because it’s still
made out of matter that used to be alive. An alive insect is organic. A dead, squished insect is
still organic. The loaf of bread in your kitchen may not seem very alive. It doesn’t get up and
walk around your kitchen, but bread is organic because it is made out of wheat, which is a plant.
Almost all the food you eat is organic, because almost all the food you eat comes from plants or
animals. Remember, inorganic means the opposite of organic. Things that are inorganic were
never alive, and are not made out of matter that used to be alive. Things like rocks, crystals, and
sand are inorganic. Because they are also solid and natural, we know that they are made out of
minerals. Remember, in order for something to be a mineral, it must be solid AND natural AND
inorganic. Two out of three doesn’t count.
There are three different types of minerals; rocks, crystals, and metals. Minerals are
homogeneous, which means they are made of the same substance all the way through. Every
part of a pure mineral should be the same color, luster, hardness, and density as every other part
of the same mineral. Rocks, on the other hand, are heterogenous, which means that they are
usually made of two or more minerals clumped together. This is why rocks can look speckled or
spotted.
Identifying Minerals
Geologists who specialize in minerals are called mineralologists. There are over 3,000 different
types of minerals in the Earth’s crust, and sometimes it can be tricky to tell them apart.
Therefore, scientists have established set physical properties for all known types of minerals to
help us identify them. Physical properties include: color, luster, streak, hardness, and density.
Today we will be looking at minerals and their physical properties. See if you can identify some
of the minerals there are a few that you may use on a daily basis. The first property that we will
be looking at is color. Remember you are working in pairs make sure you are doing your half of
the box. Take one mineral out at a time observe and record the color and then place it back in
the box before picking up another. Please be careful that you do not drop or break any of the
samples. Minerals come in many different colors. Color can be useful in figuring out what kind
of mineral something is, but a lot of the time different types of minerals are the same color as
each other, so you need to identify other physical properties to tell them apart. For instance, both
quartz crystals and diamonds are usually clear and can look the same, but they are certainly very
different minerals.
Next we will discuss luster. Luster describes how well a mineral reflects light. Minerals that
shine like glass are said to have a glassy luster. Minerals that are shiny like metal are said to
have a metallic luster. Minerals that are dull and do not reflect light well are said to have an
earthy luster. Other types of luster are resinous, greasy, silky, and pearly. As a class we will look
at a few of the common lusters. Everyone pick up mineral number 4 hold up to the light and
slowly spin it. You can see that the mineral is highly reflective and kind of looks like glass.
Scientists call this a glassy luster. Number 6 has an earthy luster it does not reflect any white and
is dull. Number 10 looks a little like metal so we say it has a metallic luster.
The next property is streak. A mineral’s streak is the color it makes when in a powdered form.
To make a mineral into a powder, we rub the mineral against a porcelain tile, just like if you
were writing on the chalkboard with a piece of chalk. In fact, chalk is a mineral, as is graphite,
which is in your pencil (not lead!). Chalk has a white streak and graphite has a dark grey streak.
However, not all minerals have a streak the same color as the mineral. Pyrite, also known as
“fools gold,” is shiny gold in color but makes a black streak, while real gold makes a golden
streak. Amethyst is a purple mineral that makes a white streak. Every box has two white and
two black porcelain tiles which we call streak plates. You only need to scratch the tile once with
the mineral record the color the mineral leaves behind on your sheet and then move onto the
next. There are two minerals that can not be tested, number 8 and 15. They are too thin and will
break apart. Give students ten minutes to test their minerals.
The next physical property is hardness. Some minerals are much harder or softer than others.
Scientists use Mohs’ Scale of Mineral Hardness to help identify minerals. Every mineral has a
hardness between 1 and 10 on Mohs’ Scale. The softest minerals, such as chalk and graphite,
have hardness’s of 1 or 2, while the hardest mineral, diamond, has a hardness of 10. We
determine a mineral’s hardness by trying to scratch it with something that we know the hardness
of. For instance, we know that the human fingernail has a hardness of about 2.5, so if you can
scratch a mineral with your fingernail (like the graphite in your pencil) then you know that the
hardness is less than 2.5. If you can’t scratch the mineral with your fingernail, but instead the
mineral damages your fingernail, then you know its hardness is harder than 2.5. A copper penny
has a hardness of 3.5. After you determine that a mineral is harder than your fingernail (2.5),
then you try to scratch it with a penny. If the penny scratches your mineral, then you know that
your mineral has a hardness of less than 3.5. If you already know that your mineral is harder
than 2.5 (your fingernail) but softer than 3.5 (the copper penny) then you know that your mineral
has a hardness of around 3. If the penny cannot scratch the mineral, or the mineral can actually
scratch up the penny, then you know your mineral has a hardness of more than 3.5. You
continue to use objects of known hardness to test your mineral until you can determine its
hardness. Glass has a hardness of 5.5, and steel has a hardness of 6.5. If even steel can’t scratch
your mineral, then you know that the hardness of your mineral is somewhere between 7 and 10.
A diamond is the only mineral that has a hardness of 10. Remember, harder objects will
scratch softer objects, and softer objects will usually streak onto the harder object. Be
careful when using a penny to test hardness, because if the mineral is harder than the penny, the
penny will leave a copper streak on the mineral. Don’t confuse a streak with an actual scratch! If
you’re not sure, then find a pointy corner of the mineral and see if you can scratch up the pennyif you can, then you know that the penny is softer than the mineral. The same thing goes for
glass and steel.
Density: An object’s density is how heavy it is compared to how big it is. You may have two
different minerals that are close in size but very different in weight. The heavier one is denser.
For instance, a piece of calcite weighs much less than a piece of magnetite the same size,
because magnetite is a very dense mineral and calcite is not.
Other Physical Properties: Other physical properties that help us identify minerals are crystal
structure, shape, and cleavage (which we’ll talk about next class), magnetism, and reaction to
acids. Some minerals can be identified just by tasting or smelling them!