1. Elements & Minerals
Bob Leighty
GLG Physical Geology

2. These notes and web links are your primary “lecture” content in this class. Additionally, various articles are assigned each week to supplement this “lecture” information. I believe you’ll have enough information to reference without having to purchase a costly textbook.
These lecture notes are very similar to the ones I use in my traditional classes. You’ll find they are loaded with imagery and streamlined text that highlight the most essential terms and concepts. The notes provide a framework for learning and, by themselves, are not meant to be a comprehensive source of information.
To take advantage of the global knowledge base known as the Internet, I have included numerous hyperlinks to external web sites (like the Wikipedia, USGS, NASA, etc.). Follow the links and scan them for relevant info. The information from linked web sites is meant to supplement and reinforce the lecture notes – you won’t be responsible for knowing everything contained in them.
As a distance learning student, you need to explore and understand the content more independently than in a traditional class. As always, I will help guide you through this learning adventure. Remember, Dr. Bob if you have any questions about today’s lecture
Leave no questions behind!
Explore and have fun!

3. Rocks, Minerals, & Elements
Elements and Minerals
Rocks, Minerals, & Elements
Rocks  Minerals  Atoms

4. Rocks, Minerals, & Elements
Elements and Minerals
rocks
granite
Rocks = a collection of one or more minerals
quartz + feldspar + biotite
minerals
Minerals = a collection of one or more elements (atoms)
atoms
quartz = silicon + oxygen

5. What’s in an Atom? Nucleus
Elements and Minerals
Nucleus
> protons = dense particles, (+) electrical charge
> neutrons = dense particles, neutral electrical charge
Electrons = light particles, (-) electrical charge

6. Elements and Minerals
It’s Elemental
An element is the word used for separating different types of atoms (H, O, C, etc.)
The # of protons in the nucleus determines the type of atom (element)
> an atom with 6 protons = the element carbon
> all C atoms have 6 protons
> all K atoms have 19 protons
> all U atoms have 92 protons

7. It’s Elemental Isotopes
Elements and Minerals
Isotopes
In any element, the number of neutrons can vary
6 protons & 6 neutrons: mass number = 12 = 12C
6 protons & 7 neutrons: mass number = 13 = 13C
6 protons & 8 neutrons: mass number = 14 = 14C
These variations of the same element are called isotopes

8. Atomic Building Blocks
Elements and Minerals
WWW
There are 117 known elements (as of 2006), but only 92 occur naturally
Earth’s Crust

9. Cl gains an e- & becomes a (-) charged ion (Cl-)
Atomic Bonding
Elements and Minerals
Ions
When atoms gain or lose e-, they become ions
Na loses an e- & becomes
a (+) charged ion (Na+)
Cl gains an e- & becomes a (-) charged ion (Cl-)

10. Atomic Bonding
Elements and Minerals
Bonding of atoms is largely determined by the # of electrons in the outermost electron shell of an atom O H
A water molecule
Salt water

11. Elements and Minerals
Atomic Bonding

12. Example: Rock salt - Sodium (Na) and Chlorine (Cl)
Elements and Minerals
Atomic Bonding
WWW
Ionic
Example: Rock salt - Sodium (Na) and Chlorine (Cl)
Atoms “loan” electrons
Bonds are weak (e.g., soluble in water)

13. WWW Atomic Bonding Covalent Atoms “share” electrons Bonds are strong
Elements and Minerals
WWW
Covalent
Atoms “share” electrons
Example: Diamond (C)
Bonds are strong

14. Making Minerals Minerals are the combination of one or more elements
Elements and Minerals
Minerals are the combination of one or more elements
> Occur naturally (not manmade)
> Inorganic
> Orderly internal structure
> Definite chemical composition

15. Rock-forming Minerals
Elements and Minerals
WWW
Concept Maps
Graphical summaries that show relations between various terms and concepts
Click here for more examples of concept maps
Click on the image to see a larger version.

16. Rock-forming Minerals
Elements and Minerals
WWW
Silicates
Basic building blocks: 1 Si + 4 O = a silica tetrahedron
Combine other elements (e.g., Mg, Fe, Al, etc.) with different arrangements of silica tetrahedra Si 4+ O 2-

17. Rock-forming Minerals
Elements and Minerals
Rock-forming Minerals
WWW
Silicates
sheets
isolated tetrahedra
single chains
double chains
3-D frameworks

18. Rock-forming Minerals
Elements and Minerals
WWW
Carbonates
Basic building blocks: 1 C + 3 O
calcite

19. Rock-forming Minerals
Elements and Minerals
Sulfides
Sulfides
Native
elements
Oxides
Carbonates
Halides
Silicates

20. Physical Properties of Minerals
Elements and Minerals
WWW

21. Physical Properties of Minerals
Elements and Minerals
WWW
Luster
How a mineral reflects light

22. Physical Properties of Minerals
Elements and Minerals
WWW
Hardness
Resistance to scratching

23. Physical Properties of Minerals
Elements and Minerals
WWW
Cleavage
Planes of weakness in a mineral
calcite
mica

24. Physical Properties of Minerals
Elements and Minerals
Color
Largely dependant on composition
Smokey quartz
Quartz
Amethyst (purple quartz)

25. Physical Properties of Minerals
Elements and Minerals
WWW
Streak
The color of a mineral when powdered
Hematite displaying a reddish streak

26. Physical Properties of Minerals
Elements and Minerals
Physical Properties of Minerals
Specific Gravity
Density of a mineral relative to water (1.0 g/cm3)
higher (10-20 g/cm3)
lower (2-3 g/cm3)

27. Physical Properties of Minerals
Elements and Minerals
WWW
Crystal Form
Unique forms controlled by a mineral’s atomic structure

28. Physical Properties of Minerals
Elements and Minerals
Physical Properties of Minerals
Others
magnetism
effervescence
fluorescence
Crystal striations

29. WWW Links in this Lecture
Elements and Minerals
> Rocks -
> Minerals -
> Atoms -
> Element -
> Nucleus -
> Protons - > Neutrons -
> Electrons -
> Isotopes -
> Periodic Table of the Elements -
> Ion -
> Electron Shell -
> Ionic bond -
> Halite -
> Covalent bond -
> Diamond -
> Concept maps -
>

30. WWW Links in this Lecture
Elements and Minerals
> Silicate -
> Silicate minerals -
> Carbonate -
> Sulfide -
> Sulfate -
> Oxide -
> Halide -
> Physical properties -
> Luster -
> Mineral hardness -
> Cleavage (crystal) -
> Streak -
> Crystal form -
> Magnetism -
> Effervescence -
> Fluorescence -