Transcript Minerals and Formation

Atoms to Minerals
MATTER: "anything that has mass and volume"
 3 Phases
Solid / Liquid /Gas
Elements: can not be separated naturally into smaller parts
 C carbon
 N nitrogen
 O Oxygen
Compounds: a chemical substance formed from 2 or more elements.
 Water (H2O)
 Halite (NaCl)
Chemical Formulas
 Calcite (CaCo3)
An atom contains an electron cloud surrounding a
nucleus composed of a proton and neutron.
Electrons have a (e-) charge
Protons have a (+) charge
Neutrons have a (Ø) neutral charge
The number of Protons is equal to the number of Electrons.
The atomic number =
The number of protons in a nucleus.
It determines the chemical properties of an element
The mass number=
Number of
protons + number of neutrons
Covalent “Sharing” Bonds
Ionic “Borrowing” Bonds
Before
After
There are seven orbital paths that
an electron can travel in.
The 1 st orbital path can only hold two electrons.
The 2nd can hold 8 e'
The 3rd can hold 18e'
The 4th can hold 32 e'
The 5th can hold 21 e'
The 6th can hold 9 e
The 7th can hold 2 e'
Mineral formation
Most minerals crystallize
from MAGMA or LAVA,
Molten material is a liquid
mixture of freely moving
crystals.
As molten material cools
crystalline solids form.
Water can also produce
minerals by evaporation
and chemical precipitation.
The type of mineral formed depends on two factors.
1. Types of element in the magma….
2. The melting point of each mineral….
Minerals with high melting point will crystallize first.
Slow cooling promotes large crystals
Fast cooling promotes fine grained or small crystals
Minerals and Rocks
A. Minerals "The building blocks of rocks”
1. Defined as…
a. Naturally Occurring
b. Crystal Structure
c. Inorganic (nonliving)
d. Have a specific internal
arrangement of atoms
2. Chemical composition of Minerals
a. can be a single element
ex. (Au) Gold (Ag) Silver
b. can be a compound
ex. Calcite CaCo3
3. Rocks can be…
a. Polyminerallic: Composed of two or more minerals
ex. Granite
Mica
Quartz
Feldspar
b. Monominerallic: Composed of one mineral
ex. Quartzite
Quartz
B . Minerals can be identified on physical or chemical properties
“Determined by their specific arrangement of atoms.”
1. Physical Characteristics
a. Color
b. Streak
c. Hardness
d. Luster
a.
e. Cleavage
f. Specific Gravity
g. Crystal Structure
Color "outside color of mineral"
Impurities discolor a mineral
b.
Streak "powdered form of mineral true color"
streak or no streak
c.
Hardness "Scratch Test" Used to Identify
minerals by the process of elimination.
 Moh's Scale of Hardness
http://www.gwydir.demon.co.uk/jo/minerals/hardness.htm
d.
Luster: Looks like a metal or not.
Metallic
Non-Metallic (glassy, pearly, earthy)
e. Crystal Structure: Minerals that grow in ideal
conditions have a crystalline shape that is
determined by their I.A.A.’s
Silicon Tetrahedron
Silicon =
Oxygen =
Atoms
Geometric Figure w/ 4
faces. Silicon at the
center oxygen on the
corners.
Crystals with
Tetrahedrons are called
Silicates.
http://www.usd.edu/esci/figures/BluePlanet.html
3. ESRT Common Minerals & Elements
Most abounded elements
in the lithosphere
-Oxygen
-Silicon
Combine to form chains or sheets.
F.
Cleavage: Mineral will split along a flat surface of
weakness.
-
Due to internal arrangement of atoms.
 Halite
Mica
Conchoidal Fracture: Breaks into a chunk.
 Opal
 Quartz
g. Specific Gravity (Density)
-Arrangement of atoms and packing determines the density
2. Chemical & Special Properties
a.
Acid Test: Minerals Bubble (Calcite)
b.
Taste (Halite)
c.
Double Refraction: (Calcite)
d. Magnetism (Magnetite)
Summery
The Chemical and Physical Properties of a mineral
are determined by the internal arrangement of
atoms.