Mineral Identification Lab
Introduction: In this lab activity you will become
familiar with minerals and identifying their different
properties. This lab will also introduce you to the
deductive process where you will utilize the results of
each property test to identify the name of the mineral
from an established key.
Safety: Goggles and gloves must be warn at all
times
Materials:
• 9 unidentified
Minerals
• Streak plate
• Nail
• File
• Magnet
• Penny
Procedure:
1. Place your name, date, class period, and bag
number on your answer sheet.
2. Take all materials out of the bag and place
them on your desk.
3. Go through and test each mineral for:
§ Hardness
§ Color
§ Streak
§ Luster
§ Cleavage/f
racture
§ Heft
4. Be sure to record all information in the data
table
YOU WILL NOT KNOW THE MINERAL
NAME TILL THE END OF THE LAB!!!
5. As your testing your minerals be sure to
record your findings on your record sheet
6. After you have tested all 9 minerals for all 6
properties, compare your test results for
each mineral to the established mineral chart
in the back. Use this chart to identify the
mineral name.
Property Descriptions and Testing Procedures:
Color: This is probably the most easily observed
property of minerals. However, color often varies
widely and is the least reliable property for
identification.
Streak: The color of the mineral when powdered.
To test for streak, draw the mineral against an
unglazed porcelain tile (streak plate). Streak is more
useful for identification than color is.
Hardness: A mineral’s hardness is it’s resistance to
scratching. Mohs Scale of Hardness, this scale uses
common everyday objects to test hardness of each
mineral sample. Below is the resulting table.
Moh’s scale of
Hardness
Rating Object used to
test Hardness
1
2
3
4
5
6
7
8
9
10
Fingernail-2.5
Penny-3.5
Nail-4.5
Glass-5.5
Steel file-6.5
Streak plate-7
Cleavage or fracture: These two properties refer to
the way in which a mineral breaks. Cleavage is an
orderly breakage in well-defined planes, meaning the
mineral has flat sides. Fracture is a random
breakage. If a mineral breaks with rough, random
surfaces, it is said to have fracture.
Heft: Compare the relative “heft” of a mineral by
holding it in your hand and comparing it to other
minerals of about the same size. In general, metallic
minerals are heavier than non-metallic minerals. For
ease minerals are classified as 1.) light, 2.) heavy, 3.)
very heavy.
Luster: Refers to the way that a mineral reflects
light. The simplest distinction is between metallic
luster (shiny and gold or silver color) and nonmetallic
luster (does not look like a metal in color, although it
may be shiny). Particular types of nonmetallic luster
include pearly, vitreous (glassy), resinous (has the
appearance of resin), silky, and earthy (dull).
Other properties: Here are three additional tests
that you should perform on all your rocks. If you get
a positive test, record it in your OTHER
PROPERTIES COLUMN.
• TASTE TEST: Certain Minerals have a
particular taste. Two minerals halide and quartz
are very similar in appearance. One simple way
to tell them apart is that halide has a salty taste
where as quartz has no taste.
• SMELL TEST: Certain minerals give off a very
distinct smell. Sulfur for instance smells like
rotten eggs
• ACID TEST: You should test all your rocks to
see if they will react with hydrochloric acid.
Place all your rocks on a paper towel and put a
single drop on each rock, one at a time. If you
immediately see a vigorous fizzing in the drop, it
is calcite. Dry them a paper towel after you are
done.
• MAGNET TEST: if one of your rocks is
attracted to a magnet, it may be magnetite. But
check all the other properties too because other
iron ores are also easily magnetized.
Mineral identification Lab: Pre-lab worksheet
Read through the lab handed out to you. Answer the
following questions before you begin your lab.
1. What are the 6 properties used to identify
minerals
a.
b.
c.
d.
e.
f.
2. Briefly describe how you would test a mineral
for each of these properties
a.
b.
c.
d.
e.
f.
3. What tool is used to determine the streak of a
mineral?
Answer:___________
4. What is the name of the scale used to determine
hardness?
Answer:___________
5. What is the difference between cleavage and
fracture?
_______________________________________
___________________________
_______________________________________
_______________________________________
_______________________________________
_______________
_______________________________________
___________________________
6. What are the two major categories of luster?
Answer:___________
___
Answer:___________
___
7. List the various descriptions for Non-Metallic
Luster
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