Class Notes: Earth Materials Flashcards
What are minerals made up of?
atoms
What are rocks made up of?
minerals
What are atoms?
chemical elements
What are minerals
A mineral is a naturally occurring, inorganic, chemical compound (or rarely an element) whose component atoms are arranged into a specific, fixed, geometric pattern. Minerals not only have fixed (or slightly variable) compositions but also have specific physical properties.
What is solid planetary material (terrestrial planets, moons, asteroids, cores of gaseous planets) made of?
rocks
What are the 3 states of matter?
solid, liquid, gas
What is an element defined by?
its chemical behaviour
What 2 things make an atom stable?
- number of elections equals number of protons
2. outer shell contains 8 electrons
What is all chemical behaviour?
An attempt–through electromagnetic forces–to satisfy the two requirements. Electrons are gained, lost, or shared.
What are noble gases?
do not gain, loose, or share electrons easily
What is the unit cell?
Smallest package minimum combinations of atoms to give us chemical compounds.
What is crystal lattice?
An arrangement of points that show the atoms.
What is the crystalline structure?
arrangement of atoms in a crystal
What are the 4 important mineral features?
1) chemical composition
2) crystal structure
3) Cleavage vs fracture
4) physical properties
What is ‘chemical composition’ of minerals?
may be fixed, e.g., Au, Sio@, or may vary somewhat e.g., Olivine (peridot (Mg, Fe)2, SiO4 Which may have any ration of Mg to Fe
What is ‘crystal structure’? What is it due to? What is it controlled by?
solid bodies with specific shapes, due to growth, and controlled by geometry of the ‘unit cell’
What is ‘cleavage vs fracture’ with minerals?
Breakage surfaces
Cleavage – controlled by unit cell
Fracture – random
What is ‘physical properties’ with minerals (3 things)? What is it controlled by?
e. g., colour, hardness, magnetism
- All controlled by composition and structure of the unit cell
What are the 3 types of minerals?
1) Groupings based on chemical composition – especially the ( - ) iron or ( - ) ion group
2) Relative abundance
3) Usefulness
What are the 2 points for relative abundance with minerals?
1) Rock-forming minerals
2) Accessory minerals
What are the 3 points for the usefulness of minerals?
1) economic minerals (for metals)
2) Industrial minerals (used for physical properties of the mineral)
3) Gemstones; precious, semi-precious, costume jewelry grade
What is gangue?
What is left over from the useful mineral stuff
What is the most common minerals?
Silicate minerals
What do all silicate minerals consist of as the basic building block ?
silica tetrahedron
What forms the basis of the ‘unit cell’ for all silicates?
silica tetrahedron
What is the most important groupie of ions in the crusts and mantles of the rocky planets?
silica tetrahedron
What are the 5 optical properties?
1) colour
2) transparent
3) translucent
4) opaque
5) lustre
True or false: some minerals have fixed colours, some do not
true
What controls colour (3 things)?
- chemical composition, including “trace elements”
- crystallinity – internal arrangement of atoms, including defects
- other things
What does the colour of corundum vary from?
clear –> any colour;
opaque – dirty brown
What is corundum if it is clear?
clear – translucent gem stone
What are the two gem qualities of corundum?
sapphire and ruby
Corundum is a___crystal.
hexagonal
What are the 4 variants of corundum?
1) dirty
2) clear
3) sapphire
4) ruby
What is pure corundum?
is a clear, white sapphire
What are the 3 metallic elements that control colour in corundum?
1) Ti
2) Fe
3) Cr
All colour of corundum except___are sapphires.
red
What are the two main ways pure carbon occurs?
diamond and graphite
___is fairy common on Earth, mainly in the crust and occurs in a number of different ways
Carbon
Graphite and diamond also occur in___, ___also occur in ___as___.
- iron meteorites
- diamonds
- chrondites
- pre-solar grains
What is the most common and important chemical composition group?
silicate groups
What do silicates contain?
Silicon (Si) and Oxygen (O)
Besides silicon and oxygen, what is the dos important other elements silicates?
Aluminum (Al)
What is the most common type of mineral in Earth’s crust and mantle?
silicates
What is the most common mineral in our moon?
silicates
What is the most common type of mineral in all terrestrial planets and moons (except for Fe-rich cores)?
silicates
What is the most common type of mineral in asteroids (except for Fe asteroids and core)?
silicates
What is the charge (valence) of Si?
+4
What is the charge (valence) of O?
-2
What is the total charge total of oxygen?
-8 because there are 4 oxygen atoms total 4 x (-2) = -8
The silica tetrahedron is a “charged” body of___. So it will___combine with various elements.
-8 + 4 = -4
What are the 2 major igneous rock types?
1) extrusive (volcanic)
2) intrusive
What are the 3 major sedimentary rocks types?
1) clastic (e.g. sandstone)
2) chemical (e.g., salt)
3) organic (e.g., coal)
What are metamorphic rocks originally? What is the term for the original material?
- Either igneous or sedimentary
- Protolith (original material)
Under what conditions do metamorphic rocks form?
High pressure and temperature but below melting
Where do metamorphic rocks form?
form at depth in Earth’s crust
How do metamorphic rocks become exposed?
Through uplift and erosion
