What is a Mineral? A mineral is a naturally formed, inorganic solid that has a definite crystalline...

What is a Mineral?A mineral is a naturally formed, inorganic solid that has a definite crystalline structure and chemical composition.

What is a Mineral?1. naturally formed2. Inorganic3. solid.4. Crystalline structure5. Definite chemical composition

(5) Characteristics of Minerals• Naturally Formed- must form naturally, not man-

made• Ex._______________ Non-ex.___________• Fossils *electronics• Apples, fruits, vegetables *paper• Trees * clothes• Water• rocks

Natural: you can find it in NATURE

Naturally Formed or Man-Made?

Naturally Formed

Man-Made (You cannot walk outside and pick up laptops and cell phones off trees).

Naturally Formed (We do not make fruit; fruit grows naturally form the earth).

Naturally Formed (found in nature)

Man-Made

Naturally formed or man-made?

(5) Characteristics of Minerals• Inorganic- cannot arise from

materials that were once part of a living thing

• Ex.______________ Non-Ex._________________

• Most rocks *decaying leaves• Water *tree• Clouds *fossils

A Mineral is Inorganic

it's never alive, it never will be

Inorganic or NOT?

Inorganic

Inorganic or NOT?

NOT! Leaves were once from a living tree.

Inorganic or NOT?

Inorganic

Inorganic or NOT?

Inorganic

Inorganic or NOT?

NOT! A tree is living.

Inorganic or NOT?

organic (fossils are formed from the remains of once living organisms).

(5) Characteristics of Minerals• Solid- always solid, not a liquid or gas. It has a

definite volume and a definite shape

(5) Characteristics of Minerals• Crystalline Structure- particles must line up in a

pattern that repeats over and over again

Crystals• Crystals are solid, geometric forms produced by a

repeating pattern of atoms or molecules that are present throughout the mineral.

• A crystal’s shape is determined by the arrangement of the atoms or molecules within the crystal.

• All minerals can be grouped into crystal classes according to the kinds of crystals they form.

Crystal Structure

Crystal StructureCrystals have a definite pattern….. This crystal prism has a pattern or design that it creates as light passes through it.

(5) Characteristics of Minerals• Definite Chemical Composition- always contains

certain elements in definite proportions. NaCl (salt)

(5) Characteristics of Minerals• Solid- always solid, not a liquid or gas. It has a

definite volume and a definite shape• Naturally Formed- must form naturally, not man-

made• Inorganic- cannot arise from materials that were

once part of a living thing• Crystalline Structure- particles must line up in a

pattern that repeats over and over again• Definite Chemical Composition- always contains

certain elements in definite proportions. NaCl (salt)

Properties of Minerals

Properties of Minerals• A mineral is a naturally formed, inorganic solid that

has a crystal structure and a definite chemical composition.

• Each mineral has its own set of specific physical properties that can be used to identify it (hardness, color, streak, luster, density, crystal system, cleavage and fracture).

• An element is a substance composed of a single kind of atom.

• A compound is two or more elements combined so that the elements no longer have their original distinct properties.

Identifying Minerals• Hardness- Moh’s scale ranks ten minerals from softest

to hardest. Resistance to scratch• Color- Because of factors, such as impurities, used

only to identify a few minerals• Streak- the color of a mineral in its powdered form• Luster- how a mineral reflects light from its surface• Density- the ratio of the mass to the volume of a

substance• Crystal Systems- six groups of structures based on the

number and angle of the crystal faces• Cleavage – splitting along smooth, flat surface• Fracture- breaking apart along curved or irregular

surfaces

Identifying Minerals

• Properties: Color, Luster, Streak, Density, Hardness, Cleavage, Fracture, and Special Properties

Color• The same mineral can

come in a variety of colors– Ex. quartz

• Impurities & other factors can change mineral appearance

• Color is not the best way to identify minerals

Luster

• Describes how a surface reflects light– Ex. shiny/dull

• Metallic- minerals containing metals are often shiny

Luster

• Examples of Nonmetallic– Vitreous- glassy, brilliant– Silky-fibrous– Resinous-plastic– Waxy- greasy, oily– Pearly- creamy– Earthy- rough, dull

Nonmetallic- not as shiny

Streak

• Color of mineral in powder form

• Observed by rubbing a mineral against a piece of unglazed porcelain called a streak plate

• Streak doesn’t vary like color & is often different than a mineral’s color

• More reliable than color

Cleavage and Fracture

Cleavage and Fracture- ways the mineral breaks apart, determined by arrangement of atoms.

Hardness• Minerals resistance to being scratched• Mohs’ Hardness Scale: Ranks minerals from softest to

hardest• Talc- softest known mineral• Diamond- hardest known mineral

Hardness

Mohs Hardness Scale• Talc 1 Softest known mineral• Gypsum 2 fingernail can scratch it• Calcite 3 scratched by copper penny• Fluorite 4 easily scratched by steel knife• Apatite 5 can be scratched by steel knife• Orthoclase 6 can scratch window glass• Quartz 7 can scratch steel• Topaz 8 can scratch quartz• Corundum 9 can scratch topaz• Diamond 10 hardest known mineral

Density

• mass (how heavy it is) per unit volume (how much space it takes up)

• D= M/V• Density remains same regardless of sample size• Mass determined using balance• Volume determined using water

displacement method.

• Ex: gold is heavier than pyrite (fools gold)

Special Properties• Some properties are particular to only a few types of

minerals:

• Fluorescence – glow under ultraviolet light• Chemical Reactions – reacts to an acid• Magnetism – natural magnets that attract iron.• Taste – ex. Halite has a salty taste• Optical Properties – some can cause a double image• Radioactivity – minerals that contain radium or

uranium

Fluorescence – glow under ultraviolet light.

Chemical Reactions- reacts to an acid.

Magnetism

Optical Properties – some can cause a double image

Special Properties of Some Minerals

Quick Check

1. Which of the following properties of minerals does Moh's scale measure?

a. lusterb. densityc. hardnessd. streak

Quick Check

2. Pure substances cannot be broken down into simpler substances by ordinary chemical means are called

a. molecules.b. compounds.c. crystals.d. elements.

Quick Check

3. Which of the following properties is considered a special property that applies to only a few minerals?

a. lusterb. tastec. hardnessd. density

Quick Check

3. The appearance of a material that can vary according to the impurities in that mineral as well as other factors:

a. densityb. cleavagec. hardnessd. streake. colorf. luster

Quick Check

4. The splitting of a mineral along smooth, flat surfaces:

a. densityb. cleavagec. hardnessd. streake. fracturef. luster

Quick Check

the ratio of the mass of a substance to the volume of the substance:


Quick Check

A measure of the ability of a mineral to resist scratching:

a. densityb. cleavagec. hardnessd. streake. fracturef. special properties

Quick Check

Characteristics that are particular to only a few types of minerals:

a, cleavageb. hardnessc. special propertiesd. streake. colorf. luster

Quick Check

The color of the powder of a mineral:a. densityb. cleavagec. hardnessd. streake. special propertiesf. color

Quick Check

5. The way in which a mineral reflects light:


Quick Check

6. The breaking of a mineral along either curved or irregular surfaces:

a. densityb. cleavagec. hardnessd. fracturee. lusterf. special properties

What is a Mineral? A mineral is a naturally formed, inorganic solid that has a definite crystalline...

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