2. INTRODUCTION/ DIRECTIONS
Welcome Junior Geologist today
we will find out if an object is a
rock or mineral!
Your task is to gather as much
information about minerals. You
must copy the information in RED
but you are not limited to just
that (You may gather more
information as needed) that is up
3. LEARNING GOALS
1. Identify properties of minerals and be able to
identify certain minerals using specific tests.
2. Apply Moh’s hardness scale to identify
minerals.
Question: What methods can we use to
identify minerals?
Minerals are most often identified by
inspecting their PHYSICAL and
Chemical properties.
11. Minerals are elements or compounds that are found
naturally in rocks or soil.
All minerals share certain characteristics and have
these things in common:
• Minerals are not found as liquids or gases. They are all
solids.
• Minerals form naturally. They are not created by people.
• Minerals form an orderly, repetitive arrangement. The
atoms that minerals are made are connected to each
other in a pattern. Fluorite often forms beautiful cube-
shaped crystals.
• Each mineral has a unique chemical composition
which also means it has its own chemical formula. The
chemical formula for fluorite is CaF2 (calcium fluoride).
12. PROPERTIES OF
MINERALS
USE THE NEXT SLIDES TO ANSWER THE BOTTOM HALF OF THE PAPER
GEOLOGISTS USE CHARACTERISTICS TO
TELL ONE MINERAL FROM ANOTHER
13. MINERALS ARE IDENTIFIED BY THEIR KEY
CHARACTERISTICS: USE THE NEXT SLIDES (RED
WRITING) TO FILL IN THE ORGANIZER.
1. hardness
2. crystal
shape (form)
3. luster
4. color
5. streak
6.
cleavage/fracture
7. density (specific
gravity)
special properties
--reaction to acid
--fluorescence
--salty taste
--magnetism
14. HARDNESS:
Is measured by how easy it is to
scratch. By using Moh’s Scale
of Hardness
Geologists order the hardness by…
1. Scratched by a fingernail.
2. Scratched by a penny.
3. Scratched by a nail.
4. Scratched by a diamond.
These are not all of the tools
geologists use,
16. MOH’S HARDNESS SCALE
Mohs hardness
scale was
developed in
1812 by Friedrick
Mohs (an Austrian
mineral expert) as
a method to
identify minerals.
This scale uses 10
minerals to
represent
variations in
Facts
Facts::
18. LUSTER
Refers to the way light
reflects from the surface of
the mineral.
There are two types of luster,
Metallic: looks like polished metal.
Nonmetallic: does not look like
polished metal.
Nonmetallic can be shiny or dull.
21. STREAK
The streak of a mineral
refers to the ("powder
color") left on a streak
plate after rubbing a
mineral across its
surface.
22. GOLD
When gold is run
across a streak
plate it makes a
yellowish-gold
color.
That makes sense.
23. PYRITE OR “FOOL’S
GOLD”
When pyrite is run
across a streak plate, it
has a black or dark
green streak.
Pyrite is not worth
much money, while gold
is worth a lot. They look
alike, so miners call it
fool’s gold.
24. HEMATITE
Hematite’s color is grey,
but its streak is red.
Hema means blood.
The mineral was named
hematite because it
looked like it was
bleeding when it was
taken across a streak
plate.
30. COLOR
Most obvious, but often misleading way to
identify a mineral thus it is the least useful
because many minerals have similar color.
Different colors may result from impurities
or they can change colors in various
circumstances. This is because small amounts
of different elements can give the same
mineral different colors.
31. CLEAVAGE
Not all minerals have cleavage.
Some minerals split easily along a flat
surface. It’s the way some minerals
break along certain lines of
weakness in their structure.
Cleavages are described in terms of
their quality - how smoothly the
mineral breaks - and their difficulty -
how easy, or how hard, it is to
produce the cleavage.
The number of lines that are created when
a mineral is split will be the number of
32. GENERAL FACTS ABOUT
MINERALS
Between 2 - 3,000 have been
identified
A few are “native elements” -- made
of only one element, such as sulfur,
gold. copper, and graphite (carbon)
Most are compounds, especially the
silicate group (Si, O).
Other important groups are oxides,
carbonates, and sulfides.
34. If you have time
If you have time
try the other links.
try the other links.
Go back to ikeepbookmarks
Go back to ikeepbookmarks
MINERALS and try the other links
MINERALS and try the other links