Activator

Rock vs Mineral?

Decide if each object shown better represents a rock or a mineral. Hold up the rock side or mineral side of your page.

Example:

Rock Why? It has more than one substance, the

bristles and the handle

Chalk

Mineral

It is only made up of one substance –the same throughout

Paperclip

Mineral

It is only made of metal, and it looks the same throughout

Spiral Notebook

Rock

It has more than one substance, the metal, spiral, and the paper.

White paper

Mineral

It looks the same throughout and is all paper

Stapler

Rock

It has more than one part. It has staples and the metal body.

Spoon

Mineral

It is all metal and looks the same throughout.

Globe

.

Rock

It has metal and plastic

MineralsPart One

MineralsText pgs. 118-126

What are they?How do we identify them?

Minerals are…

Formed naturally (occurring)

Minerals are…

Made of materials that were never alive

(inorganic)

Minerals are…

SolidsHave a definite shape and volume

gold nuggets

Minerals have a…

Definite chemical composition

Minerals are…

Arranged in regular patterns and made of crystals (crystal

structure)

Some minerals are metals.

Aluminum Gold

Some examples of minerals are

Minerals form from…

Melted Materials

Dissolved in a liquid

Part Two

Text pgs. 121-126How do we identify minerals?

Properties of Minerals

Each mineral has its own specific properties that can be used to identify it. You may need to conduct some tests to identify the mineral.

Scientists classify, or group and describe, minerals in many ways. They classify minerals by color, luster, texture, hardness, and streak.

The color (physical property) of the mineral depends on the chemicals in them.

galena malachite

vanadinite sulfur

COLOR

Luster is the amount of

light reflected from the mineral’s

surface (how shiny it is). Quartz has a

glassy luster. It looks like

glass.

LUSTER

Magnetite and Purpurite have a metallic luster. They look like shiny metal.

LUSTER

Peridot has a waxy luster. It looks as if it is covered with wax.

LUSTER

Kaolinite has a dull luster. It does not reflect much light, and is not very shiny.

LUSTER

Texture describes how a mineral feels. Minerals may be rough, smooth, bumpy, or soapy. Can you guess which mineral has each texture?

Copper - ???

Gold - ???

Calcite - ???Peridot - ???

TEXTURE

Copper - SMOOTHGold - BUMPY

Calcite - ROUGHPeridot - SOAPY

TEXTURE

All minerals are hard, but some are harder than others. Scientists test the hardness of a mineral by trying to scratch it. Scientists use the Mohs Hardness Scale to rate a mineral’s hardness. Minerals at the top of the scale are soft and easy to scratch. Those at the bottom are hard and difficult to scratch.

HARDNESS

1.Talc2.Gypsum3.Calcite4.Fluorite5.Apatite6.Orthoclase/

Feldspar7.Quartz8.Topaz9.Corundum10.Diamond

Diamonds are the hardest minerals. It is almost impossible to scratch a diamond. Talc is the softest mineral. You can scratch it with your fingernail. Apatite and feldspar have medium hardnesses.

Diamond – the hardest

mineral

talc – the softest mineral

apatitefeldspar

HARDNESS

Some minerals leave a trail, or streak, when rubbed on a hard surface. Scientists classify minerals by the color of their powder. Hematite leaves a red-brown streak.

STREAK

Pyrite leaves a black streak. Rhodochrosite leaves a white streak.

image ©

Ra’ike

, CC

-SA

license

STREAK

Crystal Systems

The crystals of each mineral from atom by atom to form the mineral’s crystal structure.Geologists classify these structures into six groups based on the number and angle of the crystal faces.

Group - ExampleCubic - MagnetitieHexagonal - QuartzTetragonal – Rutile Orthorhombic - SulfurMonoclinic - AzuriteTriclinic – Microcline Feldspar

Cleavage and Fracture

A mineral that splits easily along flat surfaces has the property of cleavage.

FractureFracture describes how a mineral looks when it breaks apart in an irregular way

Density is the mass in a given space divided by its volume. No matter what the size of a mineral sample, its density is always the same.

image ©

Ra’ike

, CC

-SA

license

DENSITY

Specific Gravitya mineral’s density in water is known as its specific gravity at a

certain temperature

Examples

The specific gravity of gold is 19.3 g/cm3

Aluminum’s specific gravity is 2.70 g/cm3

Special Properties

Fluorescence – reacts to ultraviolet light

Magnetic attraction

Reacts to an acid Radioactive, Conducts electricity, etc.

Why is it important to learn about minerals?

Minerals are made as part of the Earth’s constructive process. We use these minerals in many ways in our daily lives.

Are minerals a renewable resource? Why or why not?

No, it can take many years to replace the minerals as part of the Earth’s constructive process.

Part Three

How do minerals form? text pgs. 128-132

More about how minerals form

In general, minerals can form in two ways: through crystallization of melted materials and through crystallization of materials dissolved in a liquid. The process through which atoms are arranged to from a material with a crystal structure is referred to as crystallization.

Minerals from MagmaMinerals form as hot magma cools inside the Earth’s crust or as lava hardens on the surface. When liquids cool to a solid state, they form crystals. The size of the crystal depends on several factors: the rate at which magma cools, the amount of gas the magma contains, and the chemical composition of the magma all affect crystal size.

When magma/lava cools slowly deep in the Earth’s surface, large crystals form.When magma/lava cools quickly, small crystals form.

Minerals from hot water solutions time lapse of growing crystal

Sometimes minerals dissolve in solutions. A solution is a mixture in which one substance dissolves in another. When a hot water solution begins to cool, the elements and compounds leave the solution and begin to crystallize as minerals. Pure metals that crystallize underground form veins. A vein is a narrow channel or slab of a mineral that is different from the rock surrounding it. Often these mineral form where tectonic plates spread apart forming chimneys along the mid-ocean ridge. Other minerals can be seen when the solution evaporates. One example of this is the mineral halite (salt).

Part Four

How do we use minerals?

Mineral ResourcesText pgs. 134-139

Minerals are the sources of metals, gemstones, and other materials used to make many products that we use today.

What is an ore?

A rock that contains a metal or economically useful mineral is called an ore. Most metals do not occur in pure form. A metal usually occurs as a mineral in a combination of metal and other elements. Much of the world’s copper is found in an ore containing the mineral chalcopyrite. They must be separated from their other elements in the ore. Bauxite is an ore for aluminum.

SmeltingOres must be processed before the metals they contain can be used. After miners remove ore from a mine, smelting is necessary to remove the metal from the ore. In the process of smelting, an ore is melted to separate the useful metal from the other elements the ore contains.

After smelting, additional processing may be needed to get rid of impurities. One example is the creation of steel, an alloy – a solid mixture of two or more metals.How steel is made

Get ready to Rock!