Transcript MINERALS AND THEIR PROPERTIES

WHAT IS A MINERAL?
 A MINERAL
IS A:
 SOLID
 NATURALLY OCCURING (made up
of elements)
 INORGANIC
 CRYSTAL SHAPE (unique to the
mineral)
 CHEMICAL COMPOSITION
(elements bond together to make a
compound)
WHAT DOES THAT MEAN?
Naturally Occurring = NOT man-made
 Inorganic = NOT made of/from a living thing
 Crystal Shape = Repeating pattern of atoms


Chemical Composition = chemical formula
 Ex: Quartz has a chemical formula of SiO2
NOT A MINERAL?
COAL IS NOT A
MINERAL, WHY?
It is not inorganic
because it formed
from the remains of
living organisms
It does not have a
crystal shape
NOT A MINERAL?

PEARL IS ALSO NOT A MINERAL, WHY?
Pearls are organic
because they are
made from
oysters.
They do not have a
crystal shape
NOT A MINERAL?

GLASS IS ALSO NOT A MINERAL, WHY?
Glass does not
a crystal shape.
NOT A MINERAL?

STEEL IS ALSO NOT A MINERAL, WHY?
1: It is man-made (not naturally occurring)
2: It does not have a chemical composition
because it is a mixture of iron and carbon
3: It does not have a crystal shape
“Diamonds are Forever” Reading

Before you Read:
 Review the definition of a mineral (SNICC)

After you Read:
 Answer these questions:
○ Can the LifeGem diamonds be considered true
minerals? Explain your answer.
○ How are these diamonds different than diamonds mined
out of the ground?
○ Would you want to use this company for yourself or for a
relative?
TWO GROUPS OF MINERALS
Silicate Minerals
Nonsilicate Minerals
•Have both Silicon (Si) and
Oxygen (O) elements in them
•Do NOT contain Silicon and
Oxygen
•Make up more than 90% of
Earth’s crust
• Dividing into different classes
depending on elements in them
•Might have other elements in
them as well
•Examples: Copper (Cu)
Calcite (CaCO3)
Galena (PbS)
•Examples: Quartz (SiO2)
Talc Mg3Si4O10(OH)2
http://www.mineralogy4kids.org/groups.html
What Are Properties of Minerals???
1. COLOR

Not reliable due to:
 Impurities
 Many minerals have same color
 Some minerals have more than one
color
COLORS OF FLUORITE
2. HARDNESS
 The
ability of a mineral to resist
being scratched.
 Relative to the hardness of other
minerals and objects
 2 scales
 Field hardness scale
 Moh’s hardness scale
HARDNESS
FIELD HARDNESS
SCALE
 Fingernail
 Copper Penny
 Steel Nail
 Glass Plate
 Steel File
MOH’S HARDNESS SCALE
1.
2.
3.
4.
5.
Talc
Gypsum
Calcite
Fluorite
Apatite
6. Feldspar
7. Quartz
8. Topaz
9. Corundum
10.Diamond
3. LUSTER
 The
way a mineral reflects light
 Either Metallic or Nonmetallic
 Never described as “shiny” (that is
what luster means)
METALLIC
LUSTERS
Shines like a metal:
Chrome, Silver, Copper,
Gold, Bronze, Lead, etc.
NONMETALLIC LUSTERS
Brilliant (High Shine/Sparkly)
 Pearly or Silky
 Glassy(Vitreous)
 Waxy/Greasy
 Dull
 Earthy

4. STREAK
Powdered residue left behind when
rubbed across a porcelain tile
 Only works for minerals with a hardness
less than 7 (tile=7)
 Streak may be different than outer color
 More consistent/reliable than color

5. CLEAVAGE
 The
breaking of a
mineral along flat
surfaces
 Can be 1,2, or 3
directional
 3 Directions: Similar to
sides of a cube or
rhombus
Mica breaks into single sheets- 1 Directional
6. FRACTURE
Breaking of a mineral
in an uneven or
jagged fashion
 “Splintery”-splits like
wood
 “Earthy”/Uneven
 “Conchoidal”-curved
 “Fibrous”- like fibers

7. DENSITY
=
Mass per volume (g/mL)
 Every mineral has its own
unique density, regardless of its
size
○ Ex: The density of any piece of gold
will always be 19 g/mL
The density of any piece of silver
will always be 10.5 g/mL
8. CRYSTAL SHAPE
 Microscopic
shape of crystals
 Slow cooling = larger crystals
 Fast cooling = smaller crystals
 Cubic, Hexagonal, Octagonal,
Rhomboid, Trapezoidal, etc
9. SPECIAL PROPERTIES
 Magnetism
(lodestone/magnetite)
 Taste (Halite-salty)
 Acid reaction (calcite)
 Double refraction
 Fluorescence (glow in UV)
 Phosphorescence (glow continues)
 Odor (Sulfur)
 Radioactivity (Uraninite)
ScienceNow Diamond Factory

Diamond Factory Video
 (click on “Watch Diamond Factory”)