After UNIT VIII you should be able to: o Understand how mineral
crystals acquire their shape o Understand the characteristics that
define a sample as a mineral o Understand that many minerals are
composed of similar elements o Understand the connections between
minerals and rocks and that many rocks contain similar minerals o
Utilize the ESRT to determine human uses of common minerals o
Understand and be able to perform common mineral identification
tests such as: o Color o Streak o Breakage (cleavage or fracture) o
Hardness (Mohs Scale) o Acid test o Magnetism test o Luster o
Density
Slide 3
o Element o Atom o Chemical Composition o Mineral o Rock o
Organic o Inorganic o Orderly arrangement o Solidification o Lava o
Magma o Igneous o Precipitate o Evaporate o Sedimentary o
Metamorphic o Crystallize o Crystal o Appearance o Hardness o Mohs
Scale o Luster o Metallic o Non-metallic o Streak o Powdered o
Crushed o Breakage o Cleavage o Fracture o Density o Mass o Volume
o Acid o Reaction o Magnetic o Abrasive o Lubricant UNIT VIII
vocabulary you should be able to use and understand: o Scratch o
Impurities o Oxidation o Angular o Physical properties o Chemical
properties
Slide 4
5 Fundamental Mineral Characteristics Definite chemical
composition Orderly arrangement of atoms Naturally occurring
Inorganic Solid
Slide 5
What is a mineral? Minerals have a definite chemical
composition unique to that mineral The chemical properties a
mineral possesses determines what humans use that mineral for For
example, the mineral gibbsite (Al(OH) 3 ) can be processed to
release the aluminum atoms within it to be used in
manufacturing
Slide 6
Mineral Composition and Uses Use your ESRT page 16
Slide 7
Definite Chemical Composition The same elements will make up
the same minerals but impurities/oxidation may at times change
their color For example, table salt, or halite, is always
NaClcomposed of a combination of sodium (Na) and chlorine (Cl)
atoms
Slide 8
Other Mineral Uses Jewelry Electronics Abrasives Lubricants A
source of metal (ore)/other useful elements
Slide 9
What are minerals made up of? Minerals are composed of 1 or
more elements Certain elements contribute color to minerals (such
as these quartz samples), but color alone is not a definite way of
identifying them Many minerals contain the same elements Use your
ESRT to identify the elements
Slide 10
Common Mineral Uses Use your ESRT page 16
Slide 11
Orderly Arrangement of Atoms Atoms are arranged in an orderly
fashion so that a crystal forms This arrangement defines a minerals
physical properties such as crystal shape, hardness, or cleavage
For example: halite crystals and the atoms that produce them
Slide 12
Atomic Arrangement and Breakage The bonds between atoms
(internal atomic arrangement) in a given mineral determine how the
mineral breaks Even, angular breakage is known as cleavage Uneven,
rough breakage is known as fracture The cleavage of the mineral
graphite allows it to slide off in sheets when pressure is applied,
thus making it ideal as a material in pencil lead.
Slide 13
Naturally Occurring/Inorganic Solid Was not produced by life
processes or humans Is not a liquid or a gas
Slide 14
How do minerals form? Minerals crystals form due to one of
several rock-forming processes found in the rock cycle Cooling and
solidification of magma/lava Precipitating out of a solution, such
as when water evaporates leaving salt (halite) behind Undergoing
heat and/or pressure to form new minerals
Slide 15
Rocks are made up of 1 or more minerals This granite has
several minerals within it
Slide 16
Identifying minerals can be difficult, however many minerals
can be identified with a combination of simple tests. Mineral
Identification: Appearance (color) Color and appearance can help
identify some minerals, but it is usually not enough Gold
Pyrite
Slide 17
Common Colors Use your ESRT page 16
Slide 18
Mineral Identification: Hardness Hardness is a measure of how
easily a mineral can be scratched In our class hard minerals are
able to scratch glass while soft minerals do not Talc is a very
soft mineral and can be scratched by a fingernail Diamonds are the
hardest naturally occurring material and can only be scratched by
another diamond
Slide 19
Mineral Identification: Mohs Scale The Mohs Scale assigns a
number to a minerals hardness A diamond is a 10 since it is the
hardest mineral Talc, being one of the softest, is assigned a 1
Lower numbers more easily scratched
Slide 20
Hardness Values of Common Minerals Use your ESRT page 16
Slide 21
Mineral Identification: Luster There are two types of luster we
are concerned with in this course: metallic and non-metallic
Metallic luster is when a mineral appears to be made of metal
Non-metallic luster can be a variety of other colors including
minerals that look like glass
Slide 22
Luster of Common Minerals Use your ESRT page 16
Slide 23
Mineral Identification: Streak The streak of a mineral is the
powder left behind when a mineral is crushed or is rubbed against
an unglazed porcelain tile
Slide 24
Streak Use your ESRT page 16
Slide 25
Mineral Identification: Cleavage and Fracture Cleavage and
fracture describe how a mineral breaks Cleavage is a mineral
breaking along a flat plane Fracture is uneven and random
breaking
Slide 26
Breakage of Common Minerals Use your ESRT page 16
Slide 27
Mineral Identification: Density Determining a minerals density
sometimes help determine what it is Recall: Density =
mass/volume
Slide 28
Mineral Identification: Reaction with Acid/Magnetic Some
minerals bubble when acid is dripped onto them Other minerals are
magnetic
Slide 29
Other Distinguishing Characteristics Use your ESRT page 16
