Elements & Minerals Bob Leighty GLG 101 - Physical Geology.

Elements & MineralsElements & Minerals

GLG 101 - Physical GeologyGLG 101 - Physical Geology Bob LeightyBob Leighty

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, email Dr. Bob if you have any questions about today’s lecture ([email protected]).Leave no questions behind!Explore and have fun!Explore and have fun!

Rocks Minerals Atoms

Rocks, Minerals, & ElementsRocks, Minerals, & ElementsElementsElementsand Mineralsand Minerals

rocksrocks

granite

Rocks = a collection of one or more minerals

quartz + feldspar + biotite

mineralsminerals

Minerals = a collection of one or more elements (atoms)

atomsatoms

quartz = silicon + oxygen

Rocks, Minerals, & ElementsRocks, Minerals, & ElementsElementsElementsand Mineralsand Minerals

What’s in an Atom?What’s in an Atom?ElementsElementsand Mineralsand Minerals

> protons = dense particles, (+) electrical charge

> neutrons = dense particles, neutral electrical charge

Electrons = light particles, (-) electrical charge

Nucleus

The # of protons in the nucleus determines the type of atom (element)

> an atom with 6 protons = the element carbon

> all K atoms have 19 protons

> all U atoms have 92 protons

An element is the word used for separating different types of atoms (H, O, C, etc.)

> all C atoms have 6 protons

It’s ElementalIt’s ElementalElementsElementsand Mineralsand Minerals

6 protons & 8 neutrons: mass number = 14 = 14C

6 protons & 6 neutrons: mass number = 12 = 12C

6 protons & 7 neutrons: mass number = 13 = 13C

In any element, the number of neutrons can vary

These variations of the same element are called isotopes

It’s ElementalIt’s ElementalElementsElementsand Mineralsand Minerals

IsotopesIsotopes

There are 117 known elements (as of 2006), but only 92 occur naturally

Atomic Building BlocksAtomic Building BlocksElementsElementsand Mineralsand Minerals

Earth’sCrust

Na loses an e- & becomes a (+) charged ion (Na+)

Cl gains an e- & becomes a (-) charged ion (Cl-)

When atoms gain or lose e-, they become ions

Atomic BondingAtomic BondingElementsElementsand Mineralsand Minerals

IonsIons

Bonding of atoms is largely determined by the # of electrons in the outermost electron shell of an atom

Atomic BondingAtomic BondingElementsElementsand Mineralsand Minerals

OH H

A water molecule

Salt water

Atomic BondingAtomic BondingElementsElementsand Mineralsand Minerals

Atomic BondingAtomic BondingElementsElementsand Mineralsand Minerals

Atoms “loan” electrons Bonds are weak (e.g., soluble in water)

Example: Rock salt - Sodium (Na) and Chlorine (Cl)

IonicIonic

Atomic BondingAtomic BondingElementsElementsand Mineralsand Minerals

Bonds are strong

CovalentCovalent Atoms “share” electrons

Example: Diamond (C)

Making MineralsMaking MineralsElementsElementsand Mineralsand Minerals

Minerals are the combination of one or more elements

> Occur naturally (not manmade)

> Inorganic

> Orderly internal structure

> Definite chemical composition

Rock-forming MineralsRock-forming MineralsElementsElementsand Mineralsand Minerals

Concept MapsConcept Maps

Click on the image to see a larger version.

Graphical summaries thatshow relations between various terms and concepts

Click here for more examples of concept maps

Basic building blocks: 1 Si + 4 O = a silica tetrahedron

Si4+O2-

O2-

O2-O2-

SilicatesSilicates

Combine other elements (e.g., Mg, Fe, Al, etc.) with different arrangements of silica tetrahedra

Rock-forming MineralsRock-forming MineralsElementsElementsand Mineralsand Minerals

SilicatesSilicates

sheetsisolated tetrahedra

3-D frameworks

Rock-forming MineralsRock-forming MineralsElementsElementsand Mineralsand Minerals

doublechains

singlechains

CarbonatesCarbonates

Rock-forming MineralsRock-forming MineralsElementsElementsand Mineralsand Minerals

Basic building blocks: 1 C + 3 O

calcite

Rock-forming MineralsRock-forming MineralsElementsElementsand Mineralsand Minerals

Carbonates

Nativeelements

SulfidesSulfides

Oxides

Halides

Silicates

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

LusterLusterPhysical Properties of MineralsPhysical Properties of MineralsElementsElements

and Mineralsand Minerals

How a mineral reflects light

HardnessHardnessPhysical Properties of MineralsPhysical Properties of MineralsElementsElements

and Mineralsand Minerals

Resistance to scratching

CleavageCleavage

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

mica calcite

Planes of weakness in a mineral

ColorColor

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

Quartz Amethyst (purple quartz)

Smokey quartz

Largely dependant on composition

StreakStreak

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

Hematite displaying a reddish streak

The color of a mineral when powdered

higher (10-20 g/cm3) lower (2-3 g/cm3)

Specific GravitySpecific Gravity

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

Density of a mineral relative to water (1.0 g/cm3)

Crystal FormCrystal Form

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

Unique forms controlled by a mineral’s atomic structure

effervescence

Crystal striations

OthersOthers

Physical Properties of MineralsPhysical Properties of MineralsElementsElementsand Mineralsand Minerals

fluorescence

magnetism

WWW Links in this LectureWWW Links in this Lecture> Rocks - http://en.wikipedia.org/wiki/Rock> Minerals - http://en.wikipedia.org/wiki/Mineral> Atoms - http://en.wikipedia.org/wiki/Atom> Element - http://en.wikipedia.org/wiki/Chemical_element> Nucleus - http://en.wikipedia.org/wiki/Atomic_Nucleus> Protons - http://en.wikipedia.org/wiki/Protons > Neutrons - http://en.wikipedia.org/wiki/Neutrons > Electrons - http://en.wikipedia.org/wiki/Electrons> Isotopes - http://en.wikipedia.org/wiki/Isotopes> Periodic Table of the Elements - http://en.wikipedia.org/wiki/Periodic_Table> Ion - http://en.wikipedia.org/wiki/Ion> Electron Shell - http://en.wikipedia.org/wiki/Electron_shell> Ionic bond - http://en.wikipedia.org/wiki/Ionic_bond> Halite - http://en.wikipedia.org/wiki/Halite> Covalent bond - http://en.wikipedia.org/wiki/Covalent_bond> Diamond - http://en.wikipedia.org/wiki/Diamond> Concept maps - http://en.wikipedia.org/wiki/Concept_maps> http://www.mc.maricopa.edu/dept/d43/glg/Study_Aids/concept_maps/conceptmaps.html

ElementsElementsand Mineralsand Minerals

WWW Links in this LectureWWW Links in this Lecture> Silicate - http://en.wikipedia.org/wiki/Silicate> Silicate minerals - http://en.wikipedia.org/wiki/Silicate_minerals> Carbonate - http://en.wikipedia.org/wiki/Carbonate> Sulfide - http://en.wikipedia.org/wiki/Sulfide> Sulfate - http://en.wikipedia.org/wiki/Sulfate> Oxide - http://en.wikipedia.org/wiki/Oxide> Halide - http://en.wikipedia.org/wiki/Halide> Physical properties - http://en.wikipedia.org/wiki/Minerals#Physical_properties_of_minerals> Luster - http://en.wikipedia.org/wiki/Lustre> Mineral hardness - http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness> Cleavage (crystal) - http://en.wikipedia.org/wiki/Cleavage_%28crystal%29> Streak - http://en.wikipedia.org/wiki/Streak_%28mineralogy%29> Crystal form - http://en.wikipedia.org/wiki/Crystal_structure> Magnetism - http://en.wikipedia.org/wiki/Magnetism> Effervescence - http://en.wikipedia.org/wiki/Carbonation> Fluorescence - http://en.wikipedia.org/wiki/Fluorescence

ElementsElementsand Mineralsand Minerals