Good Web Sites about Minerals http galaxy einet

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 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