The importance of Minerals

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The importance of Minerals
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What makes a mineral?

• Like all matter (anything with volume and mass)
  minerals are made up of elements, or compounds of
  elements.
• Compounds
• Are elements chemically bonded together.
• It is impossible to separate a compound without
  chemical reactions occurring.
• Elements in turn are made up of atoms.
• Elements are listed in the Periodic Table of
  Elements.
• Atoms are made up of protons, neutrons and
  Electrons
• P, E, and N are in turn made up of subatomic
  particles.

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What is a mineral?

• There exists a certain set of criteria or
  standards a material must meet in order to be a
  mineral.
• The material must be naturally occurring.
• It must be in solid form.
• It must have definite chemical make up.
• Meaning the elements are always in the same
  proportion.
• It must have a definite molecular structure.
• AKA Crystal Structure
• It must be Inorganic
• That it is not now, nor has ever been alive or
  produced by a living thing.

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Minerals Elements or Compounds

• Of all the elements making up the Earths crust,
  8 main elements make up 99.09 of the crust by
  massSEE ESRT PG 1

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Minerals As Compounds

• Most minerals are compounds of these 8 elements
  in different proportions to one another.
• Look at the back page of your ESRT (Pg ___). Note
  the column labeled Composition
• These formulas represent the proportionality of
  each different mineral.
• Examples
• Halite for every 1 Na there is 1 Cl, so a 11
  proportion
• Calcite For every 1 Ca, there is 1 C and 3 oxygen

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How do compounds stay together?

• Compounds are held together by bonds
• Bonds are attractions between molecules due to
  various reasons.
• Ions Charged atoms of an element.
• Ionic Bonds
• Ideally in atoms the number of protons and
  electrons are equal.
• When they are not equal the atom tries to
  either gain an electron or lose an electron in
  order to balance out.
• If an atom has an extra electron, it is
  negatively charged
• If an atom has to few electrons, it is positively
  charged
• The positive and negative charges are attracted
  to each other.

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Metals vs. Nonmetals in Ionic Bonds

• Elements that lose electrons easily and form
  positively charged ions are classified as metals
• Elements that gain electrons easily and form
  negatively charged ions are classified as
  nonmetals.
• For this reason Ionic bonds form easily between
  metals and nonmetals.
• Examples Pyrite, Magnetite, Galena

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Covalent Bonds in Minerals

• Covalent bonds form when elements share electrons
  rather then donate or accept them.
• Covalent Bonds are common between nonmetal
  elements.
• The classic example is Water, Hydrogen and Oxygen
  are bound together this way in water.
• Is water a mineral?
• Only in SOLID phase!
• Look at the back page of your ESRT pg ___, what
  other minerals are bound in this way?
• Quartz (SiO2)

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Minerals as Elements

• Some minerals are only made up of 1 element.
• These elements are referred to as Native
  Minerals.
• Can you think of a few?
• Gold (Au), Silver (Ag), Copper (Cu),
  Sulfur (S), Diamonds (C), Graphite (C)

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How Minerals Form

• There are 4 different ways in which minerals can
  be formed.
• They can occur in loose cavities, attached to the
  walls of the cavity.
• They can precipitate out of solution as water is
  removed.
• They can form as the result of solidification of
  lava.
• They can form as existing minerals are subjected
  to high temperature and pressure.
• All methods result in the formation of crystals.
• As the minerals form they take on a definite
  crystal pattern, the size of the crystal is
  determined by the rate of cooling or
  precipitation.

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Crystal Patterns in Minerals

• All minerals are said to be Crystalline.
• This means they are made of atoms arranged in a
  pattern.
• Crystals are minerals with a geometric shape and
  smooth flat surfaces called faces.
• Each mineral has its own unique crystal shape.
• These crystal shapes are divided up into six
  basic types.
• The speed of formation determines the size of the
  crystal. (SlowLarge)

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Crystal Systems

• Cubic -
• Contains three axes of equal length.
• All axis are positioned at right-angle to each
  other.
• A cube is also referred to as a closed form and
  can itself be a crystal.
• Gold
• Copper
• Diamond
• Lazurite
• Galena
• Pyrite

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• Orthorhombic -
• Contains three axes which are of different
  lengths.
• All axis are positioned at right angles to each
  other.
• Sulfur
• Stibnite
• Topaz
• Chrysoberyl
• Aragonite
• Barite

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• Monoclinic -
• Contains three axes of unequal length.
• Two axis are not at right angles.
• The third axis is at a right angle to the plane
  containing the other two axes
• Wolframite
• Manganite
• Malachite
• Azurite
• Borax
• Gypsum

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• Triclinic -
• contains three axes.
• All axis are of different length and none at a
  right angle to the others
• Ulexite
• Axinite
• Turquoise
• Kyanite
• Rhodonite
• Heulandite

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• Tetragonal -
• contains 3 axes
• Two of which are the same length
• All are at right angles to one another
• Tourmaline
• Dolomite
• Hematite
• Corundum
• Calcite
• Idocrase

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• Hexagonal -
• Contains four axes
• Three of equal length, all three arranged in the
  horizontal plane.
• The forth axis is perpendicular to that plane and
  is of a different length to the others.
• Graphite
• Nickeline
• Molibdenite
• Apatite
• Vanadinite
• Beryl

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Common Mineral Groups

• There are 5 major groups of minerals.
• They are Silicates, Ores, Carbonates, Oxides, and
  Sulfides.

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Silicates

• Silicates are minerals made of Silicon and Oxygen
  along with other elements.
• Remember Oxygen and Silicon make up 74.3 of the
  Earth by mass!
• This type of mineral makes up the 90 of Earths
  minerals.
• The basic building block for silicates
  is the Silicon Tetrahedron.
• The tetrahedrons are held together
  by strong covalent bonds.
• The tetrahedrons can be arranged in
  sheets or chains.

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Single Silica Tetrahedral Chains

• The chains are held together by strong covalent
  bonds.

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Silica Tetrahedral Sheets.

• The tetrahedrons are held together by covalent
  bonds.
• The sheets in turn are connected to other sheets
  above or below them with weak ionic bonds.

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Ores

• Minerals that contain a high percentage of some
  commercially valuable substance (usually metals)
  are called ores.
• This includes native metallic minerals (100)
• Examples
• All form Octahedral shapes
• Form covalent bonds to one another -gt
• Iron
• Aluminum
• Lead

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Carbonates

• Carbonates are compounds of 1 carbon atom and 1
  oxygen and 1 calcium atom.
• Look at your ESRT what minerals contain 1 carbon
  and 1 oxygen and 1 Ca molecules?
• Calcite CaCO3
• Dolomite CaMg(CO3)2
• These carbonate minerals make up Limestone, and
  react with Acids to form bubbles.

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Oxides

• In oxides minerals of metallic nature chemically
  react with oxygen to form a new material.
• Examples
• Iron Oxygen Iron Oxide (AKA rust)
• Copper Oxygen Cupric Oxide (the green on
  copper roofs!)
• Look at your ESRTdo you see any metals bound
  with oxygen?
• Magnetite, Hematite,

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Sulfides

• In sulfides, minerals of metallic nature
  chemically react with sulfur to form a new
  material.
• Examples
• Look at your ESRTdo you see any metals bound
  with sulfur?
• Iron Sulfur Pyrite (AKA fools gold)
• Lead Sulfur Galena