CEEES/SC
10111-20111
Planet Earth
Mineral Identification Laboratories
The Basic Stuff:
Minerals and their Physical Properties
OBJECTIVES:
First Lab: Recognizing
the
various physical properties of minerals and how to use these to aid in
mineral identification.
Second Lab: Learning diagnostic physical properties and
how to identify minerals in hand specimen.
Click
here for a PDF file of
the lab manual chapter for the first Lab.
Click
here for a PDF file of
the lab manual chapter for Second Lab.
Mineral:
naturally occurring compound or chemical element made of atoms arranged
in an orderly, repetitive pattern.
Both chemical
composition and atomic structure characterize a mineral and determine
it’s physical properties.
A few naturally occurring substances called mineraloids
have characteristic chemical compositions, but are amorphous (i.e., atoms are not
arranged in regular patterns).
The precise chemical composition and
internal atomic structure that defines each mineral also directly
determines its outward appearance and physical properties.
Therefore, in most cases physical properties
can be used to identify minerals.
Remember: The physical properties
refer to the fresh, unaltered (unweathered) mineral.
Physical Properties
Click here for a PDF file of
the lab
handout.
MOHs Hardness scale
Cleavage
Color
Fracture (e.g., conchoidal
fracture)
Specific Gravity
Habit/Form
Streak
Luster
Other (e.g., Striations)
How to Identify a Mineral
More than 4,000 minerals are known,
but (fortunately) only a few are common. Minerals are divided
into the following groups (Table 2.1):
Rock-Forming Minerals:
the most abundant minerals at the Earth’s surface.
Minor Minerals:
maybe important constituents of certain rocks, but are rare in most
rocks.
Accessory Minerals:
commonly present in rocks, but generally only in small amounts.
Ore Minerals:
have
economic value when concentrated and are mined for the elements they
contain.