1. Earth Materials

2. Objectives
Explain the different kinds of bonds and describe their influence on mineral characteristics
Define and distinguish between minerals and rocks
List key properties used to identify minerals
Identify most common mineral families and accessory mineral families
Explain what holds rocks together

3. Elements and Compounds
the most fundamental substance into which matter can be separated using chemical means
Atom
the smallest individual particle that retains the distinct chemical properties of an element
Isotopes
Atoms with the same atomic number but different mass numbers

4. Elements and Compounds

5. Compounds, molecules and bonding
A combination of atoms of one or more elements in a specific ratio
Molecule
The smallest chemical unit that has all properties of a particular compound

6. Compounds, molecules and bonding
The force that holds together the atoms in a chemical compound
Ionic bonding
Covalent bonding
Metallic bonding
Van der Waals bonding

11. Compounds, molecules and bonding
Ionic Bonding
One atom transfers electron to another, which creates bond
Table salt (sodium chloride)
Cubic lattice
Moderate strength and hardness

12. Compounds, molecules and bonding
Covalent Bond
Electrons from different atoms “pair up”, which creates a bond
Does NOT produce ions
Strongest of chemical bonds

13. Compounds, molecules and bonding
Metallic Bond
Electrons shared among several atoms
Outer electrons may drift between each other
Typically good conductors of electricity

14. Compounds, molecules and bonding
Van der Waals Bond
Attraction between electrically neutral molecules with asymmetrical charge
Form sheets
Considered weak between sheets
May feel slippery between sheets

15. What Is a Mineral? Mineral
A naturally formed, solid, inorganic substance with a characteristic crystal structure and a specific chemical composition

16. What Is a Mineral?

17. Composition of minerals
Crystal structure
An arrangement of atoms or molecules into regular geometric lattice.
Materials that possess a crystal structure are said to be crystalline

18. Telling minerals apart
Luster
The quality and intensity of light reflection
Metallic
Vitreous
Resinous
Pearly

19. Telling minerals apart
Hardness
A mineral’s resistance to scratching

20. Telling minerals apart
Crystal form
Flat or planar surface that forms during the growth of minerals
Crystal faces
Habit
The distinctive shape of a particular mineral
Cleavage
The manner in which a mineral breaks

21. Telling minerals apart
Color
Streak
The thin layer of powder made by rubbing a specimen on an unglazed fragment of porcelain
Density
Reflection of compactness of atoms

22. Telling minerals apart
Other mineral properties
translucent, transparent or opaque
birefringent
magnetic
luminescence or fluorescence

23. Mineral families and their uses
Minerals of Earth’s crust
Silicate minerals
A strongly bonded, complex anion that contains both silicon and oxygen
Oxide minerals
Contains the simple oxide anion O2-

24. Mineral families and their uses

25. Mineral families and their uses

26. Minerals of Earth’s crust
Rock forming minerals
Polymerization
The formation of a complex molecule by the joining of repeated simpler units
Accessory minerals
Less common minerals

29. Minerals of Earth’s crust
Other mineral families
Carbonate
Sulfates
Sulfides
Phosphates

30. Mineral resources in modern society
Ore deposits
A localized concentration that can be extracted profitably.
Mining
Disturbs Earth’s surface
Damage to environment

31. Rocks: A First Look Rock
A naturally formed coherent aggregate of minerals and possibly other non-mineral matter
Record history of Earth processes

32. Rocks: A First Look Igneous Sedimentary Metamorphic
Form by cooling and solidification of molten rock
Magma
Sedimentary
Form under conditions of low pressure and low temperature near the surface
Metamorphic
Altered by exposure to high temperature, high pressure or both.

33. Rocks: A First Look What holds rocks together?
Partly mechanical, partly chemical
May be caused by:
Compaction
Solution
Recrystallization

34. Critical Thinking
Which of the following materials are minerals, and why (or why not)?
Water, beach sand, diamond, wood, vitamin pill, gold nugget, fishbone
Rock samples, taken from the Moon, contain many of the same minerals as those found on Earth. Why might this be the case?
Are there valuable ores being mined locally? If so, what are the rocks and minerals of interest?