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.
Materials:
 15 unidentified Minerals
 Streak plate
 Nail


Magnet
Penny
Procedure:
1. Place your name, date, and class period top of this sheet.
2. Read through the Pre-lab worksheet and answer the questions (page 2 &
3).
3. Self-check your answers at one of the stations set up around the room.
4. Get a mineral kit. Go through and test each mineral for:

Hardness

Cleavage/fracture

Color

Heft

Streak

Luster
5. Be sure to record all information in the data table
YOU WILL NOT KNOW THE MINERAL NAME TILL THE END OF THE LAB.
6. As you’re testing your minerals, be sure to record your findings on your
record sheet
7. After you have tested all 15 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.
What did you learn after completing this activity? Write a conclusion paragraph below:
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Mineral identification Lab: Pre-lab worksheet
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
Fingernail-2.5
3
Penny-3.5
4
Nail-4.5
5
Glass-5.5
6
Steel file-6.5
7
Streak plate-7
8-10
Diamond -10
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 Tests:
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?
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6. What are the two major categories of luster?
Answer:_______________
Answer:________________
7. List the various descriptions for Non-Metallic Luster





Mineral Name
Color
Streak
Hardness
Cleavage
or
Fracture
HEFT
Light,
Medium,
Heavy
Luster
Metallic/NonMetallic
Magnetic?
Mineral Name
Possible Colors
Streak
Hardness
HEFT
Light,
Medium,
Heavy
Luster
Metallic/NonMetallic
4
Cleavage
(how many
planes)
or
Fracture
Cleaves
Fluorite
Green, yellow,
purple
Brown
White
Medium
None
2.5-3
Cleaves 1 plane
Light
Vitreous
(glassy)
Vitreous, glassy
Calcite
Clear to milky,
orange, blue
White
3
Cleavage
Light
Glassy to earthy
Feldspar
Gray, green
orange
Colorless
6
Light
Vitreous
(glassy)
Graphite
Grey
Grey
1.2
Two planes of
cleavage that
meet at right
angles
Cleavage
Light
Metallic to
Dull
Alabaster
Gypsum
Pinkish-white,
white, grey,
reddish-brown
White
1.5-2 scratches
with fingernail
Cleaves
Light
Pearly-Earthy
Biotite
Other
Properties
Very flexible
Mineral takes a
rhombic shape
Reacts with acid
Mineral Name
Possible Colors
Streak
Hardness
Halite
Clear, white
None
2.5
Hematite
Black, grey,
reddish-brown
Grey-black
Reddish-brown
5.5-6.5
Black
6
Muscovite
Clear, white,
light brown
Colorless, light
brown
2-2.5
Pyrite
Golden-brassy,
yellow
Clear, white,
purple, rose,
grey
White, Grey
Greenish black
Selenite
Gypsum
Talc
Magnetite
Quartz
Satin Spar
Gypsum
Cleavage
(how many
planes)
or
Fracture
Cleaves at right
angles
Fracture
HEFT
Light,
Medium,
Heavy
Luster
Metallic/NonMetallic
Other
Properties
Light
Transparent
Tastes salty
Heavy
Metallic or rusty
Non cleavage,
but octahedral
parting
Cleaves in 1
plane
Heavy
Metallic
magnetic
Light
Glassy to pearly
Flat flexible
crystals
6-6.5
Fracture
Medium
Metallic
None
7
Light
Vitreous
(glassy)
White
2
No cleavage,
but conchoidal
fracture
Fracture
Light
Silky
Colorless
White
2
Cleaves into 1
plane
Light
Transparent
White, green
White
1
Cleaves
Light
Pearly-greasy
Powdery-greasy
feel