Minerals

• Write down what you know about minerals.

• What things in this room are made of minerals?

MineralsThe building blocks of

rocks

Some Chemistry Review• Atom – basic unit of

matter; smallest part of an element that keeps the element’s properties

• Element – substance that can’t be broken into simpler substances by ordinary chemical means

(What do these two terms mean in your own words?)

• Compound – a substance that contains atoms of two or more elements that are chemically combined– Ex. Water (H20) – Two hydrogen atoms

combined with one oxygen atom– This combination occurs when atoms bond in

one of many ways, all involving the electrons

Electron arrangement

• 2 electrons in the first ring• 8 electrons in the second ring• 8 electrons in the third ring• (It gets more complicated….)

• Remember: an atom wants the number of negative electrons that surround its nucleus to match its number of positive protons.

• Number of protons is the same as atomic number

Practice drawing electron configuration:

• Carbon

• Oxygen

• Hydrogen

• Silicon

Elements that make up most of the Earth’s Crust

• #1: Oxygen (O) 47%

• #2: Silicon (Si) 28%

• also Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium

What is a mineral?1. Naturally occurring (not man-

made)

2. Inorganic (not alive or made from living things)

3. Solid (not liquid or gas)

4. Definite chemical structure (each mineral always has the same atoms bonded together)

5. Crystal structure (orderly arrangement of atoms)

(A substance has to meet all five of these characteristics to be a mineral!)

Crystal Structure

• Crystal – regular geometric solid with smooth surfaces called crystal faces

• In minerals, the shape of the crystal depends mainly on the atoms of the mineral and the way they arrange themselves – Despite thousands of minerals, there are only

six basic crystal shapes

Mineral Formation and Composition

• 1. Come from Magma (molten rock beneath Earth’s surface)– When cooled, mineral crystals are formed

– How and where magma cools determines size of mineral crystal

– 2 most common elements found in magma are oxygen and silicon

• 2. Compounds are dissolved in a liquid, which evaporate leaving minerals as crystals

Questions to Discuss:1. What are the two most common

elements in the earth’s crust? In magma? Does this make sense?

2. What is the difference between an atom, an element, and a compound?

3. What are some ways to help you remember the five characteristics of a mineral?

4. Can elements be minerals? Are all elements minerals?

Which of these are minerals?Why or why not?

1. Salt?

2. Water?

3. Ice?

4. Aluminum?

5. Synthetic (man-made) diamond?

6. Sugar? (Think where it comes from)

7. Diamond?

8. Coal? (Think where it comes from)

9. Quartz?

Silicate Minerals

• Minerals that contain silicon and oxygen (and usually other elements, too)

• 96% of the minerals formed in the Earth’s crust are silicates

• Examples are:

feldspar

quartz (shown)

mica

Silica is the most abundant mineral on Earth

• Silica’s chemical composition is SiO2

• Quartz is a common name for silica

• Sketch out the covalent bonding scheme for SiO2:

Carbonates

• Carbonate minerals are made of one or more metallic elements combined with CO3 (a carbonate compound)

• Examples are:

limestone (CaCO3)

dolomite (pictured)

calcite

The dolomite mountains in Italy

Oxides

• Compounds of Oxygen + a metal

• Examples are:

magnetite (Fe3O4)

hematite (Fe2O3)

Native Elements

• Made of only one element like Au, Cu, Ag

Sulfides and Sulfates

• Sulfides are made of sulfur and one or more elements

• Sulfates are made of sulfate compound (SO4) and one or more elements

• Ex of a sulfide = pyrite (FeS2)

Halides

• Cl or F along with Ca, Na, or K

• For example?