Download minerals notes 2013

Minerals
(NOTES/Classwork)
A mineral is: (use page 39 of your workbook)
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Has atoms arranged in a crystalline structure (pattern)
Has a definite chemical composition (Ex. SiO2 will always be quartz)
Inorganic means:
Mineral Formation
Minerals form in 3 ways:
1. When magma cools crystals solidify.
2. When water evaporates and leaves behind elements. As water evaporates, the water that is left
becomes saturated with minerals, and elements/minerals will precipitate out (settle out) of the
solution. (This is where precipitate rocks come from, like limestone).
3. When old minerals form new minerals from extreme heat and pressure.
Properties of Minerals
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Determined by the INTERNAL ARRANGEMENT OF ATOMS/ELEMENTS. (physical) Chemical properties
are determined by the type of elements the mineral is made of.
Property
Test/Observation
Color
The color that the mineral appears.
Streak
Mineral is powdered against a porcelain plate. To test: hold plate on table and
drag mineral across it, observe the color of the powder if there is any.
Luster
How the mineral reflects light (metallic or non-metallic) Does it look like a piece
of metal or has pieces of metal in it?
Hardness
Mineral is scratched against a glass plate (hardness of 5.5, so if mineral scratches
glass it’s harder than 5.5, if not it’s softer) To test: Hold glass plate on table and
drag mineral across it.
Cleavage
Number of directions of smooth, flat surfaces (can occur in more than one
direction or not at all). Look for: Flat sides that catch the light all at once.
Fracture
Mineral is broken on uneven, curved surfaces.
Magnetism
Test mineral with a magnet or a paperclip. If it is attracted it is magnetic.
Reaction with HCl (acid)
Mineral will “fizz” when exposed to mild hydrochloric acid.
Fluorescence
Mineral exposed to UV light gives off visible light.
Radioactivity
Emission of energy rays or nuclear particles form the breakdown of an unstable
element.
= we will test and observe together, you have no samples with these properties
Samples observed in class:
For each container of samples, compare and contrast and try to determine what property is being shown from
the list of properties above.
Sample #
1
2
3
4
5
Similarities
Differences
Property that
could be used to
distinguish them
6
7
8
9
10
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Graphite (the stuff that makes your pencil write) and diamond (the stuff that people pay way too much
money for) are made of EXACTLY the same material, Carbon. Explain why they are so different. You
can use the following diagrams to help you explain if you need to. (Thinner lines in the pictures are
weaker bonds. The spheres are the Carbon atoms.)
Mineral Families
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According to the ESRT p.1, which two elements make up the majority of the Earth’s crust?
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According to the ESRT p.16, how many commonly occurring minerals contain these elements (out of
the 21 listed)?
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Based on the questions you answered above, circle the mineral family below that contains the minerals
that make up the majority of the Earth’s crust.
Silicates Family
 Made of silicon (Si) and
oxygen (O)
 Structured in a silica
tetrahedron (a triangular
arrangement of atoms.
Examples: Quartz, Feldspar
Carbonates Family
 Minerals made up of
carbon (C) and oxygen
(O) atoms
 Can fizz in the
presence of acid
Examples: Calcite, Dolomite
Sulfides/Oxides Family
 Made up of sulfur (S)
or oxygen (O)
 Usually contain metal
elements such as iron
 Used to make steel,
magnets, car parts,
plastics, and paints.
Examples: Hematite,
Magnetite, and Pyrite.