The boiling point of water at sea
level is 100 degrees Celsius. What
phase would you expect water to be
if it were heated to 110 degrees
Celsius?
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solid, because the molecules are moving more
slowly
liquid, because some of the molecules are still
boiling at 110 degrees
gas, all the molecules have enough energy to have
escaped at 110 degrees
1 kg of the compound toluene melts
at -95○C . What will happen to 500
g of toluene?
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Melt at -47.5 ○C
Melt at -95 ○C
Boil at 95 ○C
Boil at 47.5 ○C
As warm air rises, it cools,
condenses and freezes in the upper
atmosphere. What happens as it
falls back to Earth?
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It undergoes no chemical or physical change
It undergoes a physical change from solid to
liquid
It undergoes a physical change from solid to
gas
It undergoes a chemical change from solid to
gas
It undergoes a chemical change from a solid to
liquid
What is a Mineral?
Minerals – Can you SNIFC it?
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Definition: a naturally occuring, inorganic
solid, with a crystalline structure and
definite chemical composition
Mineral must be:
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Solid
Naturally occuring
Inorganic
Formula (or Definite chemical composition)
Crystalline structure
Mineral Characteristics
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Solid:
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Minerals are always solid.
They have a definite volume and shape.
Mineral Characteristics

Mineral = Natural occurring, inorganic solid
that has a crystal structure and a definite
chemical composition.
Mineral Characteristics

Natural Occurring:
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Formed by a process in the natural world
Mineral Quartz forms naturally as molten
material cools and hardens deep beneath
Earth’s surface.
Mineral Characteristics

Inorganic:
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Minerals cannot form from materials that were
once part of a living thing.
For example, coal forms naturally in the crust,
but it is not a mineral because it comes from the
remains of plants.
Inorganic

INORGANIC:
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Consist of non-living material
ORGANIC:

Consist of living or once living material
Coal—made by carbon atoms
from ancient trees—trees are
living—not a mineral--organic
Gold—made by gold
atoms—mineral--inorganic
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Organic? OR
inorganic?
ORGANIC VEGTABLES
Organic vs Inorganic
As a result things like pearls,
coral, coal and amber are not
considered minerals.
Also included in the “NOT a
Mineral List” are teeth,
bones, sea shells and even
kidney stones.
Barite Rose - A flower like growth
of Barite crystals.
Formula or
Definite chemical composition

Any given mineral always has the same
chemical composition. We say it has a specific
formula. Chemical formulas are a way to
describe the specific types and amounts of
atoms in a substance.

Example:
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Mineral gold: chemical composition Au (gold)
Mineral Diamond: chemical composition C (carbon)
Mineral halite: chemical composition NaCl (sodium and
chlorine)
Mineral quartz: chemical composition SiO2 (one Silicon
and 2 Oxygen)
Mineral Characteristics

Definite Chemical Composition:
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Minerals always contain certain elements in
certain amounts.
Almost all minerals are compounds.
Some elements occur in nature in a pure
form…like copper, silver, and gold.
O Si
O
O
O
Si
Si
O
O
Mineral Characteristics
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Crystal Structure:
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Particles of a mineral line
up in a pattern that
repeats over and over
again.
The repeating pattern
forms a solid called a
CRYSTAL.
Crystals have flat sides,
that meet at sharp edges
and corners.
Crystalline structure
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Unique arrangement of atoms in a crystal
Identifying Minerals
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There are about 3,800 minerals in our
world!
How do geologists identify all of them???
Identifying Minerals
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Each mineral has characteristic properties
that can be used to identify it:
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Color
Streak
Luster
Density
Hardness
Crystal Systems
Cleavage and Fracture
Special Properties
Identifying Minerals
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Color:
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The mineral malachite is always green and the
mineral azurite is always blue.
No other minerals look quite the same as these!
Their color makes them identifiable.
Identifying Minerals
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Color:
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Color is easy to observe, but is not the best way
to identify a mineral.
Which one is GOLD?
Identifying Minerals
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Streak:
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The streak of a mineral is the color of its
powder. You can observe a streak by rubbing a
mineral against a piece of unglazed porcelain
tile.
Write the definition for a
mineral in your own
words
Identifying Minerals
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Luster:
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Luster describes how light is reflected from a mineral’s
surface.
“Shininess”
Luster of Minerals
Metallic
Glassy
Waxy, Greasy, or Pearly
Submetallic or Dull
Silky
Earthy
Identifying Minerals
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Density:
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Density is how much mass is in a given space
(or volume).
Sometimes you can FEEL density by measuring
the difference of the two minerals in your hand.
Density = Mass/Volume
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To find the volume of a mineral: Place the mineral in
water to determine how much water the sample
displaces. The volume of the displaced water equals
the volume of the sample.
Identifying Minerals
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Hardness
HARDNESS is defined as the resistance a mineral
has to being scratched - its “scratchability”.
Hardness tests are done by scratching one
mineral against another. The mineral that is
scratched is softer than the other.
Pyrite Crystals
Hardness of 6.5
Identifying Minerals
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Hardness:
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Friedrich Mohs, an Austrian mineral expert,
invented a test to describe the hardness of
minerals.
The Mohs Hardness Scale ranks ten minerals
from softest to hardest.
Identifying Minerals
Mohs Hardness Scale
1
2
3
4
5
Talc
Gypsum
Calcite
Fluorite
Apatite
6
7
8
9
10
Feldspar
Quartz
Topaz
Corundum
Diamond
Mineral Identification Basics
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PHYSICAL PROPERTIES HARDNESS
In this photo, a quartz crystal was
rubbed across a glass plate. The
result is that the glass plate was
scratched. The quartz is harder than
the glass.
Quartz is harder than glass.
HINT: In doing a hardness test try to pick a
smooth or flat surface on the mineral to be
scratched. Try to pick a point or a sharp edge on
the mineral that you think will do the scratching.
Glass is usually a good place to start because it is
in the middle of the hardness table, it has a flat,
smooth surface and it is easily obtained.
Identifying Minerals
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Crystal Systems:
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All minerals are crystal
shaped
Minerals that have room
to grow form complete,
perfect crystals.
Minerals that grow in tight
places form incomplete
shapes.
Halite has a CUBIC
crystal structure.
Identifying Minerals
Identifying Minerals
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Cleavage and Fracture:
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A mineral that splits easily along flat surfaces
has the property called cleavage.
Most minerals do not split apart evenly. Instead
they have a characteristic type of fracture.
Fracture describes how a mineral looks when it
breaks apart in an irregular way.
Identifying Minerals
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Cleavage
CLEAVAGE is the property of a mineral
that allows it to break repeatedly along
smooth, flat surfaces.
These GALENA cleavage fragments
were produced when the crystal was
hit with a hammer. Note the
consistency of the 90o angles along
the edges.
These are FLUORITE cleavage
fragments.
Identifying Minerals
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Fracture
FRACTURE is defined as the way a
mineral breaks other than cleavage.
This is a piece of volcanic glass called
OBSIDIAN. Even though it is NOT a
mineral, it is shown here because it
has excellent conchoidal fracture.
Identifying Minerals
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Name 5 Properties of
Minerals
Identifying Minerals
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Special Properties:
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Magnetism: Magnetite attracts
metal like a magnet.
Fluorescence: Scheelite is a
mineral that glows in ultraviolet
light
Identifying Minerals
Special Properties:
 Optical Properties: Calcite bends light to
produce a double image.
 Reactivity with Acid: Aragonite reacts
chemically to acid.
Mineral Identification Basics
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PHYSICAL PROPERTIES HARDNESS
MOH’S SCALE OF MINERAL HARDNESS
1. TALC
6. FELDSPAR
2. GYPSUM
3. CALCITE
4. FLUORITE
5. APATITE (*)
7. QUARTZ
8. TOPAZ
9. CORUNDUM
10. DIAMOND
OTHER MATERIALS COMMONLY USED:
Moh’s scale is a list of minerals with increasing hardness.(*)
2.5 - FINGERNAIL
3 - COPPER PENNY
4 – Iron Nail
5.5 - GLASS
6-6.5 - STEEL FILE
7 – Ceramic Tile
Observing Mineral Properties
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On a separate piece of paper make this
table:
Mineral Name
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Color
Streak
Luster
(use the
ceramic tile)
(use your
notes!)
Hardness Cleavage or
(harder or
Fracture?
softer than a
penny?)