Download What is a mineral?

EQ: What is a mineral?
Standard: S6E5.b
Investigate the contribution
of minerals to rock
composition.
EQ: What is a mineral?
• What are the
characteristics of a
mineral?
• What is a crystal, and
what determines a
crystal’s shape?
• Describe the two major
groups of minerals.
• What is a native element?
Mineral Structure
• A mineral is a naturally formed, inorganic
solid that has a define crystalline structure.
• Minerals may be either elements or
compounds.
• Elements are pure substances that cannot
be broken down into simpler substances by
ordinary means.
• A compound is a substance made of two
or more elements that have been
chemically joined together.
Properties of Minerals
• Naturally Formed- must form naturally, not
man-made
• Inorganic- cannot arise from materials that
were once part of a living thing
• Solid- always solid, not a liquid or gas. It
has a definite volume and a definite shape
• Crystalline Structure- particles must line up
in a pattern that repeats over and over again
• Definite Chemical Composition- always
contains certain elements in definite
proportions. NaCl (salt)
Mineral Structure
• A few minerals, such as gold and silver,
are composed of only one element.
• A mineral that is composed of only one
element is called a native element.
• Native elements are used in
communications, and electronics
equipment.
Crystals
• A crystal is a solid whose atoms, ions, or
molecules are arranged in a definite pattern.
• Crystals are solid, geometric forms produced
by a repeating pattern of atoms or molecules
that are present throughout the mineral.
• A crystal’s shape is determined by the
arrangement of the atoms or molecules within
the crystal.
• All minerals can be grouped into crystal
classes according to the kinds of crystals
they form.
Two Groups of Minerals
• Minerals are divided into two groups based on
their chemical composition.
• Silicate minerals are minerals that contain a
combination of the elements silicon and oxygen
(quartz, feldspar, mica).
• Silicate minerals make up over 90% of the
Earth’s crust.
• Nonsilicate minerals are minerals that do not
contain a combination of the elements silicon
and oxygen ( copper, calcite, fluorite, corundum,
gypsum, galena).
Quick Check
What are the two major groups of
minerals?
a.
b.
c.
d.
metallic and nonmetallic
native elements and carbonates
silicates and nonsilicates
quartz and mica
Quick Check
Which of the following is NOT a
characteristic of a mineral?
a. It is formed in nature.
b. It is a living material.
c. It has a crystalline structure.
d. It is a solid.
Quick Check
A mineral that contains a combination of
silicon, oxygen, and other elements is a
a.
b.
c.
d.
crystal.
Silicate mineral.
nonsilicate mineral.
element.
Quick Check
Which of the following is a nonsilicate
mineral?
a.
b.
c.
d.
orthoclase, KASi3O8
Talc, Mg3Si4O10(OH)2
Almandine, Fe3Al2(SiO4)3
Magnetite, Fe3O4
Quick Check
A solid whose atoms, ions, or molecules
are arranged in a definite pattern is called
a
a. silicate mineral
b. element.
c. Crystal.
d. nonsilicate mineral.
Quick Check
A mineral that does not contain
compounds of silicon and oxygen is called
a
a. mineral.
b. silicate mineral.
c. compound.
d. Nonsilicate mineral.
Quick Check
A substance that cannot be separated or
broken down into simpler substances by
chemical means is called an
a. Element.
b. crystal.
c. mineral.
d. compound.
Quick Check
A naturally formed, inorganic solid that has
a definite crystalline structure is called a
a. silicate mineral.
b. nonsilicate mineral.
c. crystal.
d. Mineral.
Quick Check
A substance made up of atoms of two or
more different elements by chemical
means is called a
a. silicate mineral.
b. mineral.
c. Compound.
d. element.
EQ: How are minerals identified?
• How are minerals
identified?
• What is the Mohs
hardness scale?
• What is the major
difference between an
element and a
compound?
Properties of Minerals
• A mineral is a naturally formed, inorganic
solid that has a crystal structure and a
definite chemical composition.
• Each mineral has its own set of specific physical
properties that can be used to identify it
(hardness, color, streak, luster, density, crystal
system, cleavage and fracture).
• An element is a substance composed of a
single kind of atom.
• A compound is two or more elements
combined so that the elements no longer
have their original distinct properties.
Identifying Minerals
• Hardness- Mohs hardness scale ranks ten
minerals from softest to hardest.
• Color- Because of factors, such as impurities,
used only to identify a few minerals
• Streak- the color of a mineral in its powdered form
• Luster- how a mineral reflects light from its
surface
• Density- the ratio of the mass to the volume of
a substance
• Crystal Systems- six groups of structures based
on the number and angle of the crystal faces
• Cleavage – splitting along smooth, flat surface
• Fracture- breaking apart along curved or irregular
surfaces
Special Properties
• Some properties are particular to only a few
types of minerals:
•
•
•
•
•
Fluorescence – glow under ultraviolet light
Chemical Reactions – reacts to an acid
Magnetism – natural magnets that attract iron.
Taste – ex. Halite has a salty taste
Optical Properties – some can cause a double
image
• Radioactivity – minerals that contain radium or
uranium
Mohs Hardness Scale
•
•
•
•
•
•
•
•
•
•
Talc
Gypsum
Calcite
Fluorite
Apatite
Orthoclase
Quartz
Topaz
Corundum
Diamond
1
2
3
4
5
6
7
8
9
10
Softest known mineral
fingernail can scratch it
scratched by copper penny
easily scratched by steel knife
can be scratched by steel knife
can scratch window glass
can scratch steel
can scratch quartz
can scratch topaz
hardest known mineral
Quick Check
Which of the following properties of
minerals does Moh's scale measure?
a.
b.
c.
d.
luster
density
hardness
streak
Quick Check
Pure substances cannot be broken down
into simpler substances by ordinary
chemical means are called
a. molecules.
b. compounds.
c. crystals.
d. elements.
Quick Check
Which of the following properties is
considered a special property that applies
to only a few minerals?
a. luster
b. taste
c. hardness
d. density
Quick Check
The appearance of a material that can vary
according to the impurities in that mineral as well
as other factors:
a. density
b. cleavage
c. hardness
d. streak
e. color
f. luster
Quick Check
The splitting of a mineral along smooth, flat
surfaces:
a. density
b. cleavage
c. hardness
d. streak
e. fracture
f. luster
Quick Check
the ratio of the mass of a substance to the
volume of the substance:
a. density
b. cleavage
c. hardness
d. streak
e. fracture
f. luster
Quick Check
A measure of the ability of a mineral to
resist scratching:
a. density
b. cleavage
c. hardness
d. streak
e. fracture
f. special properties
Quick Check
Characteristics that are particular to only a
few types of minerals:
a, cleavage
b. hardness
c. special properties
d. streak
e. color
f. luster
Quick Check
The color of the powder of a mineral:
a. density
b. cleavage
c. hardness
d. streak
e. special properties
f. color
Quick Check
The way in which a mineral reflects light:
a. density
b. cleavage
c. hardness
d. streak
e. fracture
f. luster
Quick Check
The breaking of a mineral along either
curved or irregular surfaces:
a. density
b. cleavage
c. hardness
d. fracture
e. luster
f. special properties
The Formation, Mining, and Use of
Minerals (p.74)
• Where can you find
minerals?
• What is an ore?
• Compare surface and
subsurface mining.
• What is reclamation?
• What are some examples
of minerals and their
uses?
The Formation of Minerals
• Minerals form in a variety of environments
in Earth’s crust.
• Each of these environments has a
different set of physical and chemical
conditions.
• The environment in which a mineral forms
determines the mineral’s properties.
• Environments in which minerals form may
be on or near Earth’s surface or deep
beneath Earth’s surface.
The Environments
Evaporating Salt Water
• When a body of salt water dries up,
minerals are left behind.
-gypsum, halite
Metamorphic Rocks
• When changes in temperature, pressure,
or chemical make-up changes a rock,
metamorphism takes place.
• -calcite, garnet, graphite, hematite,
magnetite, mica, and talc
The Environments
Limestones
• Surface water and ground water carry dissolved
materials to lakes and seas where they
crystallize on the bottom
-Calcite, dolomite
Hot-Water Solutions
• Groundwater works its way downward and is
heated by magma. It then reacts with minerals
to form a hot liquid solution.
-gold, copper, sulfur, pyrite, galena
The Environments
Pegmatites
• As magma moves upward, it can form teardropshaped bodies called pegmatites. The mineral
crystals become extremely large.
-many gemstones, such as topaz, tourmaline
Plutons
• As magma rises upward through the crust, it
sometimes stops moving before it reaches the
surface and cools slowly, forming millions of
mineral crystals. The entire magma body
solidifies to form a pluton.
– Mica, feldspar, magnetite, quartz
Mining
• An ore is the natural material large enough and
pure enough to be mined for profit.
• Rocks and minerals are removed from the
ground by one of two methods-surface mining
and subsurface mining.
• Surface mining is used to remove mineral
deposits on or near the Earth’s surface.
- open pits
- surface coal mines (open-pit)
- quarries
Mining
• Subsurface mining is used when mineral
deposits are located too deep within Earth to be
surface mined.
• Mine reclamation is the process by which land
used for mining is returned to its original state or
better.
• Has been required by law since the mid-1970’s.
• To reduce the effects of mining, reduce our need
for minerals.
• Recycle!
The Use of Minerals
• Some minerals are of major economic and
industrial importance.
• Metallic minerals have shiny surfaces, do
not let light pass through them, good
conductors of heat and electricity.
• Nonmetallic minerals have shiny or dull
surfaces, may let light pass through them,
and are good insulators of electricity.
The Use of Minerals
• Gemstones are highly valuable minerals
because of their beauty and rarity rather
than their usefulness.
• Color is the most important characteristic
of a gemstone.
• The more attractive the color is, the more
valuable the gem is.
• Mass of a gem is expressed in a unit
known as a carat.
• One carat is equal to 200 mg.
Common Uses of Minerals
Mineral
Uses
Copper
Electrical wires, plumbing, coins
Diamond
Jewelry, cutting tools, drill bits
Galena
Batteries, ammunition
Gibbsite
Cans, foil, appliances, utensils
Gold
Jewelry, computers, spacecraft, dentistry
Gypsum
Wallboards, plaster, cement
Halite
Nutrition, highway de-icer, water softener
Quartz
Glass, computer chips
Silver
Jewelry, photography, electronic products
Sphalerite
Jet aircraft, spacecraft, paints
Quick Check
• In a mineral, the particles line up in a
repeating pattern to form
•
•
•
•
A.
B.
C.
D.
an element
a crystal
a mixture
a compound
Quick Check
• The term that describes how a mineral
reflects light is its __________.
•
•
•
•
A. luster.
B. streak
C. color.
D. weight.
Quick Check
• One characteristic that a substance must
have to be considered a mineral is _____.
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•
•
A. to be living.
B. to be small.
C. to a liquid.
D. to be a solid.
Quick check
• A compound is two or more ________
chemically combined.
•
•
•
•
A. atoms
B. minerals
C. elements
D. protons
Quick Check
• An element is a substance composed of a
single kind of __________.
•
•
•
•
A. compound.
B. atom.
C. mineral.
D. Mohs hardness scale.
Quick Check
•
The groupings silicate and nonsilicate
minerals are based on
a.
b.
c.
d.
Organic content.
Gas and liquid state
Chemical composition.
Color.
Quick Check
•
Nonsilicate minerals
a.
b.
c.
d.
Do not contain oxygen.
Include native elements.
All have a nonmetallic luster.
Are all rare substances.
Quick Check
Which of the following is NOT a class of
nonsilicate minerals?
a.
b.
c.
d.
oxides
Micas
carbonates
native elements
Quick Check
What is a mineral deposit that is large and
pure enough to be mined called?
a.
b.
c.
d.
gemstone
ore
pluton
pegmatite
Quick Check
Halides form when fluorine, chlorine, or
bromine combine with any of the
following elements EXCEPT
a.
b.
c.
d.
sodium.
potassium.
calcium.
oxygen.
Quick Check
•
What is the name for nonmetallic
minerals that are valued for their beauty
and rarity rather than their usefulness?
a.
b.
c.
d.
plutons
gemstones
ores
pegmaites
Quick Check
•
What kinds of mines are open pit and
quarry mines?
a.
b.
c.
d.
shaft mines
slope mines
surface mines
subsurface mines