MINERALS

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• The building blocks of minerals are elements.

MINERALS

• An element is a substance that cannot be broken down into simpler substances by chemical or physical means.

CHEMISTRY AND MINERALS

• Atom-The smallest particle of matter that contains the characteristics of an element.

• Parts of an Atom:• Neutron• Proton• Electron

CHEMISTRY AND MINERALS CONT…

• Protons• Positively

Charged• Found in the

nucleus.• # of

protons=atomic number

• Neutron• No charge• Found in the

nucleus.• Has the same

mass as protons.

PROTONS AND NEUTRONS

• Negatively charged

• Located in energy levels surrounding the nucleus.

• 1/1836 the mass of a proton.

ELECTRONS

Atoms with the same number of protons, but different numbers of neutrons.

ISOTOPES

• A compound is a substance that consists of two or more elements that are chemically combined in specific proportions.

• Chemical Bonds are the forces that hold atoms together in a compound.

BONDING

TYPES OF BONDS

Ionic Covalent Metallic

Transfer of electrons Sharing of electrons between two atoms

Sharing of electrons between metal ions.

Metal and Nonmetal Nonmetal and Nonmetal

Metals and Metals

Table Salt (NaCl) Water or Sugar Alloys (Brass)

Minerals are naturally occurring, inorganic solids with an orderly crystalline structure and definite chemical composition.

MINERALS!!!!

1. Crystallization from Magma

2. Precipitation

3. Pressure and Temperature

4. Hydrothermal Solutions

HOW MINERALS FORM

• As magma cools, elements combine to form minerals.

• Crystal structure depends on the rate of cooling and pressure.

• First to crystallize:• Rich in iron, calcium, and

magnesium.

• Second to crystallize:

• Rich in sodium, potassium, and aluminum.

CRYSTALLIZATION

• Water evaporates, some dissolved substances can react to form minerals

• Two common examples

• Limestone and Halite

PRECIPITATION

• An increase in pressure can cause minerals to recrystallize while still solid.

• Changes in temperature can also cause certain minerals to become unstable and rearrange into a configuration that is more stable at the new conditions.

• Common Examples:• Muscovite and Talc

PRESSURE AND TEMPERATURE

• Hot mixture of water and dissolved substances.

• Temps. Between 100-300°C

• When they come into contact with existing minerals, chemical reactions take place to form new minerals.

• Examples:• Chalcopyrite, bornite, and

pyrite

HYDROTHERMAL SOLUTIONS

MINERAL GROUPS

Common minerals can be classified into groups based on their composition.

• Silicates

• Carbonates

• Oxides

• Sulfates/Sulfides

• Halides

• Native Elements

• The most common group of minerals on Earth.

• Silicon and oxygen combine to form a structure called the silicon-oxygen tetrahedron.

• Examples: Micas, Olivine, Quartz, and Hornblende

SILICATES

• 2nd most common mineral group.

• Carbonates are minerals that contain the elements carbon, oxygen, and one or more other metallic elements.

• Examples: Calcite, Dolomite

CARBONATES

• Oxides are minerals that contain oxygen and one or more other elements, which are usually metals.

• Examples: Corundum and hematite

OXIDES

• Sulfates and sulfides are minerals that contain the element sulfur.

• Examples: Pyrite, Galena, Sphalerite

SULFATES/SULFIDES

• Halides are minerals that contain a halogen ion plus one or more other elements.

• Examples: Halite and fluorite

HALIDES

• Native elements are a group of minerals that exist in relatively pure form.

• Example: Gold, Silver

NATIVE ELEMENTS

• Color• Streak• Luster• Crystal Form

• Hardness• Cleavage• Fracture• Density• *Other

Distinctive Properties

PROPERTIES OF MINERALS

• Color• not usually

helpful in identifying a mineral.

• Streak• The color of a

mineral in its powdered form.

PROPERTIES OF MINERALS

• Luster:• how light is

reflected.• Metallic: shiny• Nonmetallic:

earthy, silky, or glassy

• Crystal Form• visible expression

of a mineral’s internal arrangement of atoms.

• Well-developed crystals form slowly and without space restrictions.

PROPERTIES OF MINERAL

• Hardness• The measure of the

resistance of a mineral to being scratched.

• Mohs Hardness Scale: consists of 10 minerals arranged form 10 (hardest) to 1 (softest)

PROPERTIES OF MINERALS

• Cleavage:• The tendency of

a mineral to cleave, or break, along flat, even surfaces.

• Fracture:• Uneven

breakage.

PROPERTIES OF MINERALS

• Density:• Mass/volume• Pure minerals

have constant densities.

PROPERTIES OF MINERALS

• Texture/Feel• Talc feels soapy.

• Magnetism• Magnetite is magnetic

• Smell• Sulfur has a rotten

egg smell.

• Acid Reaction• Calcite reacts with

HCl

DISTINCTIVE MINERAL PROPERTIES