1-1    Minerals vs. Rocks:

1-1-1    Rocks: aggregates of minerals, normally more than one kind. Granite has quartz, feldspar, etc.. Sometimes one type of mineral, e.g. calcite in limestone.

1-1-2    Minerals:

• Natural occurring. Thus, synthetic materials such as manmade diamond are not.
• Have definite chemical composition and internal structure. Thus glass is not.
• Solid. Thus, water is not.
• Inorganic. Thus, coal is not.

1-2    Composition and Structure of Minerals:

1-2-1    Atoms:

• Basic particles that make up the element and thus the substances.
• Atoms from the same element are alike, and from different elements are different, e.g. O atom in H₂O and in CO₂ are the same. But O atom is different from H atom.
• Composed of nucleus and electrons. Within nucleus there are protons and neutrons.
• Neutron have no charge. Each proton has one "+" charge while each electron has one "-" charge.
• The whole atom is electrically neutral since the number of protons = the number of electrons.

1-2-2    Ions:

• When atoms lose or gains electrons.
• Cations have "+" charge due to loss of electrons, e.g. Na⁺.
• Anions have "-" charge due to gaining of electrons, e.g. Cl^-.
• Interaction between cations and anions are called ionic bonds, which hold the cations and anions together.

1-3    Properties of minerals:

1-3-1    Crystal form:

• shape of crystals, some are cubic, and others are rhombohedral (Fig 1.5).

• reflect the internal arrangement of its composing atoms

1-3-2    Luster:

light reflection from the surface of minerals

classified as metallic and nonmetallic (hand specimens)

1-3-3    Color:

1-3-4    Streak:

• the color of a mineral in its powder form.

• Sometimes, the color and the streak will be different for a mineral

• to test you need a ceramic plate, then scratch the mineral against it, color left on the plate is called.

• streak more important than color in identifying minerals.

1-3-5    Hardness:

• a measure of resistance against abrasion.

• use mohs scale

Hardness of common tools:

• glass, knife 5.5

• copper penny 3.5

• Finger nail 2.5

1-3-6    Cleavage (Fig. 1.5 and 1.6): the tendency to break along weak planes

Distinguish cleavage from crystal form:

• there is only one crystal form in each direction, once the form is broken you lose it.

• cleavage has a set of plane parallel to each direction, you can generate a new piece by breaking the old one.

1-3-7    Specific gravity: weight of a mineral to the weight of water having the same volume.

metallic minerals normally have high S. G.

1-3-8    Other properties:

magnetism, fluorescence, radioactivity, etc.

1-4    Mineral groups:

1-4-1    Most abundant elements:

O, Si, Al, Fe, Na, K, Ca, Mg.

1-4-2    Rock forming minerals:

• the materials that make up common rocks.

• made of Si and O, commonly called silicates.

• In silicates, Si is in the center fo SiO4 tetrahedron (Fig 1.10)

• depending on the connection of SiO4 tetrahedra, silicates are classified as (Fig 1.11)

1-4-3    Nonsilicates:

based on the type of anions.

1-4-4    Mineral Resources:

Reserves: resources that can be extracted and utilized now.

Deposits: resources that can't be recovered under current technologies.

Ore: metallic minerals that can be used to extract metals. Sometimes, refer to nonmetallic minerals that have economic values, too. However, the minerals or rocks for construction purpose is called inductrial rocks and minerals.

Homework:

• Read chapter summary

• Use your own word to explain the key terms on page 32.

• Answer the review questions.