Download minerals - Marian High School

MINERALS
BUILDING
BLOCKS OF
ROCKS
MINERALS
•Matter
= anything that takes
up space & has mass
MINERALS
• Element = a substance
which cannot be
broken down by a
chemical change.
• Atom = smallest unit
of an element that has
all the properties of
that element.
MINERALS
• Nucleus =
center of atom
•Electron Cloud
= region of
atom around nucleus
where electrons can
be found
MINERALS
Subatomic Particles
PROTON
MASS
1 amu
CHARGE
positive
(+)
LOCATION
nucleus
NEUTRON ELECTRON
1 amu
0
none
negative
(-)
nucleus
electron
cloud
MINERALS
Classifying Elements:
• Atomic Number = number of
protons
– determines type of element
• Mass Number = number of
protons + number of neutrons
in nucleus
• Symbols = 1 or 2 letters that
represent each element
MINERALS
Classifying Elements:
• Isotopes = atoms with the
same number of protons and
different numbers of neutrons.
MINERALS
ATOMIC BONDS
• Atoms combine with each
other to form compounds.
• Compound = two or more
elements chemically combined
in a specific ratio.
• Atoms bond with each other to
have 8 e- in their outermost
energy level.
MINERALS
ATOMIC BONDS
1. IONIC
2. COVALENT
3. METALLIC
ATOMIC BONDS
1. IONIC
• form between positive & negative
ions
• ion = atom that has gained or lost e• ionic compound – combination of
metal & nonmetals (Group 1 or 2
with Group 16 or 17)
• form when e- transfer from one atom
to another
–
–
–
high melting & boiling points
poor conductor of electricity in solid state
good conductor of electricity when
melted
ATOMIC BONDS
2. COVALENT
• form when atoms share e• covalent compounds - form
between elements on right side of
periodic table
• smallest particle = molecule
• properties
–
–
low melting & boiling points
poor conductors of electricity
ATOMIC BONDS
3.
•
•
•
•
•
METALLIC
form when metal ions share epool of mobile emalleable = easily shaped
ductile = pulled into wire
excellent conductors of
electricity
MINERALS
Periodic Table
• organizes elements
• Periods (rows) – elements
have electrons with similar
valence energy levels
• Groups/Families (columns)
– elements have similar
electron configuration
– have similar chemical
properties
MINERALS
5 Criteria:
1. Naturally occurring
2. Inorganic
3. Solid
4. Crystalline = a solid whose
atoms
have a specific
internal arrangement.
5. Definite chemical composition
MINERALS
• Physical Property
= a characteristic that can be
observed without changing the
composition of the substance.
• Observations include
measurements.
• Examples: color, density, mass,
volume, melting point,
hardness
MINERALS
• Chemical Property
=a characteristic that
describes how a substance
interacts with other substances
to form new, different
substances.
MINERALS
• minerals – made from elements
• atoms = smallest particles of
elements

3 particles make up atoms:



protons = positive charge
neutrons = NO charge
electrons = negative charge
• ion = atom that has gained or
lost e-
PROPERTIES of MINERALS
1. COLOR
• easily observed
• some minerals have distinct
colors
• Unreliable:
– many minerals have similar colors
– trace amounts of other elements
affect the color
– weathering changes surface color
quartz
fluorite
calcite
CALCITE
QUARTZ
PROPERTIES of MINERALS
2. LUSTER
= how a mineral reflects light
• Metallic – reflects like
polished metal
• Nonmetallic – everything else
PROPERTIES of MINERALS
Metallic
PROPERTIES of MINERALS
Nonmetallic
glassy
(vitreous)
brilliant
(adamantine)
pearly
earthy
silky
PROPERTIES of MINERALS
3. STREAK
= color of powdered mineral
• rub mineral sample against a
streak plate
• minerals that contain metals
leave a dark streak
• minerals that contain
nonmetals leave a pale or
colorless streak
PROPERTIES of MINERALS
4. HARDNESS
= ability of a mineral to resist
scratching
• does not indicate how well it
resists breaking
PROPERTIES of MINERALS
4. HARDNESS
• Quick hardness test – Can it
scratch glass?
– Yes = hard mineral
– No = soft mineral
• some minerals have a
hardness range
PROPERTIES of MINERALS
Mohs Hardness Scale
• 10 minerals with accepted
hardness values
• hardness established by:
– scratching unknown with tools of
known hardness
– using unknown to scratch tools of
known hardness
PROPERTIES of MINERALS
Mohs Hardness Scale
1.Talc
2.Gypsum
3.Calcite
4.Fluorite
5.Apatite
6.Feldspar
7.Quartz
8.Topaz
9.Corundum
10.Diamond
PROPERTIES of MINERALS
Hardness testing tools:
• fingernail = 2.5
• copper penny = 3.5
• iron nail = 4.5
• knife blade = 5.0
• piece of glass = 5.5
• steel file = 6.5
• streak plate = 7.5
PROPERTIES of MINERALS
5. CLEAVAGE & FRACTURE
• Cleavage = tendency to break
along planes of weakness and
form parallel sides
– planes of weakness occur where
atomic bonds are weak
– related to crystal structure
Cleavage
PROPERTIES
of MINERALS
5. CLEAVAGE &
FRACTURE
• Fracture =
surface of broken
mineral is uneven
& irregular
– mineral lacks
cleavage planes
PROPERTIES of MINERALS
6. DENSITY
• also called specific gravity
• range for most minerals:
2.5 – 3.5 g/cm3
• minerals containing heavy
metals: 7 – 20 g/cm3
PROPERTIES of MINERALS
7. CRYSTAL SHAPE
• related to the arrangement of
atoms within the mineral
quartz
halite
PROPERTIES of MINERALS
Other Properties
• Reaction with acid
• Magnetism
• Flexibility
• Conductivity
• Double Image
• Radioactivity
• Fluorescence
PROPERTIES of MINERALS
Fluorescence
IDENTIFYING MINERALS
1.
2.
3.
4.
5.
6.
7.
COLOR
LUSTER
STREAK*
HARDNESS*
CLEAVAGE & FRACTURE*
DENSITY*
CRYSTAL SHAPE
* RELIABLE PROPERTIES
PROPERTIES of MINERALS
http://webmineral.com/crystall.sht
ml
PROPERTIES of MINERALS
http://www.minsocam.org/MSA
/K12/crystals/xlsystems.html