Ch. 6 Rocks and Minerals
I. Minerals: _________________ occurring,_________________ solids, with _______________ structure and
composition; made of one or more elements
A. Characteristics of Minerals:
1. Formed by ____________________________________________
2. Inorganic (not formed from life processes)
3. Solid
4. Definite chemical _____________________________, can have minor variations (example: salt is NaCl)
5. _____________________ arranged in a __________________________
B Structure of Minerals: minerals are in the form of _______________________________ (a solid in which the atoms
are arranged in repeating patterns)
C. Crystal Systems: Examples of Perfect Crystal Systems
Examples:
______________________________- Cubic-Halite (salt); Platinum
______________________________-Zircon; Wulfenite
_____________________________-Quartz; Corundum
1. The first group is the ISOMETRIC. This literally means “______________________________________” and refers to
the equal size of the crystal axes.
2. HEXAGONAL Crystal Axes Three _____________________ axes meeting at angles of 120o and one perpendicular axis.
3. TETRAGONAL Two equal, horizontal, mutually __________________________ axes Vertical axis is perpendicular to
the horizontal axes and is of a different length.
D. How Minerals Form:
1. Form from the ______________ of hot melted rock (_________________); If it cools fast, crystals tend to be small;
cools slow, larger crystals tend to form
2. Form from _________________________-as liquid _______________________, minerals solidify and form crystals.
E. Major Mineral Groups:
1.____________-Made of Silicon, Oxygen, & possibly other element(s); largest group of minerals Example: Quartz (SiO2)
2. ____________-Made of Carbon, Oxygen, & possibly other elements. Examples: Calcite (CaCO3); Magnetite (MgCO3)
F. Most Abundant Elements in Earth’s Crust: (glue in notes)
G. Physical Properties of Minerals:
1. _______________________-a measure of how easily a mineral can be scratched
2. ______________________- Describes how light is reflected from a mineral’s surface: Metallic, Nonmetallic, dull;
pearly; silky; glassy; brilliant; transparent, Waxy, Resinous (looks like freshly broken shellac)
3. ________________________- The color seen when looking at the surface of the mineral; Least reliable property
because many minerals can be many colors
Example: Sulfur is pale yellow
4._________________________ - The color of the mineral when it’s broken up in powdered form; Use a porcelain tile to
test; Useful for softer minerals; Minerals with a hardness greater than 7 do not leave a streak Example: Gold has a gray
streak
5. The way a mineral breaks:
A. _______________________-When a mineral breaks along smooth, flat surfaces; Example: Mica
B ________________________When minerals break with rough or jagged edges; Example: Quartz
6. ___________________________________- Unusual or unique qualities; Examples: Magnetite is magnetic, Calcite has
optical qualities, Jade has a bell-like ring when tapped, Halite has a salty taste, and Sulfur smells like rotten eggs
Uses of Minerals:
H. _____________________Highly prized minerals because they are rare and considered beautiful; the difference in a
gem and the common form of a mineral can be slight
I. _________________________-contain useful substances that can be mined for a profit
Examples: Bauxite contains Aluminum; Hematite contains Iron; Sphalerite contains Zinc; Chalcopyrite contains copper
A. __________________________-Removing ore by digging at Earth’s surface; usually results in a huge pit
B. _________________________ mining companies are required to return soil and rock to open pit and cover it
with topsoil then plant trees and grass
C. ____________________________a mineral with threadlike, flexible fibers used as insulation and as fire
protection; has been shown to cause lung diseases including lung cancer
D. ___________ (Environmental Protection Agency)-requires school officials to inspect buildings every six
months; flaking asbestos must be removed or sealed over
Minerals can contain other useful elements.
1_______________________ must be refined, or purified, from ores
2. Some elements dissolve in _________________, travel through weaknesses in rocks, and in those
weaknesses form mineral deposits called vein mineral deposits
3. __________________________ is useful element derived from the minerals limonite and rutile
III. ______________________ – made of one or more minerals
A. ______________________________ form from molten material from a volcano or deep inside Earth;
Examples: Obsidian, Granite, & Pumice
B________________________- Form as a result of processes at or near Earth’s surface; Examples: Halite
(rock salt), Limestone, Calcite, & Sandstone C._____________________- Form from changes due to
temperature and pressure increases; can form from all 3 rock types; Examples: Slate & Marble