Transcript Good Web Sites about Minerals:

Good Web Sites about
Minerals:
• http://galaxy.einet.net/images/ge
ms/gems-icons.html
• Smithsonian Gem and Mineral
Collection -- lots of spectacular
mineral pictures and good
information
The Rock
Cycle
A model that
describes all the
crustal processes
by which rock is
formed,
modified,
transported,
decomposed,
and reformed.
N.Lindsley-Griffin, 1999
Rocks are made up of minerals
N. Lindsley-Griffin, 1999
What is a Mineral?
• Occurs naturally
• Not previously living
(inorganic)
• Solid
• Definite chemical
composition
• Orderly internal
atomic arrangement
N. Lindsley-Griffin, 1998
Ivory, bone, seashells, coral, petrified wood,
and other previously living things…
are NOT minerals
N. Lindsley-Griffin, 1998
Minerals
are made
up of
atoms
Atomic number =
number of protons;
gives atoms their
distinctive
characteristics.
Atomic mass =
protons plus neutrons
N. Lindsley-Griffin, 2000
Ions combine to form compounds
Here, the Li atom loses an electron to become a +
positively charged cation. The F atom gains an
electron to become a negatively charged anion.
Positive and negative charges attract each other to
form an IONIC BOND
N. Lindsley-Griffin, 1999
Covalent Bonding -- atoms share electrons
to form a strong bond.
Diamond
Diamond and graphite are the same
chemical composition (Carbon) but
exhibit very different internal structures.
Graphite
N. Lindsley-Griffin, 1999
Van der Waals Bonding -- a weak bond
caused by a weak secondary attraction
between molecules.
Graphite
N. Lindsley-Griffin, 1999
Orderly array of atoms in the mineral
Galena:
large atoms - sulfur, small - lead
As seen with a scanning-tunneling microscope
N. Lindsley-Griffin, 1999
The orderly arrangement of atoms in
Galena controls its physical properties.
Error in textbook on
Figure 2.7: Sulfur
atoms, not “oxygen”
Sulfur atom
N. Lindsley-Griffin, 1999